linux/security/selinux/hooks.c
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   1/*
   2 *  NSA Security-Enhanced Linux (SELinux) security module
   3 *
   4 *  This file contains the SELinux hook function implementations.
   5 *
   6 *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
   7 *            Chris Vance, <cvance@nai.com>
   8 *            Wayne Salamon, <wsalamon@nai.com>
   9 *            James Morris <jmorris@redhat.com>
  10 *
  11 *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
  12 *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
  13 *                                         Eric Paris <eparis@redhat.com>
  14 *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  15 *                          <dgoeddel@trustedcs.com>
  16 *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
  17 *      Paul Moore <paul.moore@hp.com>
  18 *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
  19 *                     Yuichi Nakamura <ynakam@hitachisoft.jp>
  20 *
  21 *      This program is free software; you can redistribute it and/or modify
  22 *      it under the terms of the GNU General Public License version 2,
  23 *      as published by the Free Software Foundation.
  24 */
  25
  26#include <linux/init.h>
  27#include <linux/kernel.h>
  28#include <linux/tracehook.h>
  29#include <linux/errno.h>
  30#include <linux/sched.h>
  31#include <linux/security.h>
  32#include <linux/xattr.h>
  33#include <linux/capability.h>
  34#include <linux/unistd.h>
  35#include <linux/mm.h>
  36#include <linux/mman.h>
  37#include <linux/slab.h>
  38#include <linux/pagemap.h>
  39#include <linux/swap.h>
  40#include <linux/spinlock.h>
  41#include <linux/syscalls.h>
  42#include <linux/file.h>
  43#include <linux/fdtable.h>
  44#include <linux/namei.h>
  45#include <linux/mount.h>
  46#include <linux/proc_fs.h>
  47#include <linux/netfilter_ipv4.h>
  48#include <linux/netfilter_ipv6.h>
  49#include <linux/tty.h>
  50#include <net/icmp.h>
  51#include <net/ip.h>             /* for local_port_range[] */
  52#include <net/tcp.h>            /* struct or_callable used in sock_rcv_skb */
  53#include <net/net_namespace.h>
  54#include <net/netlabel.h>
  55#include <linux/uaccess.h>
  56#include <asm/ioctls.h>
  57#include <asm/atomic.h>
  58#include <linux/bitops.h>
  59#include <linux/interrupt.h>
  60#include <linux/netdevice.h>    /* for network interface checks */
  61#include <linux/netlink.h>
  62#include <linux/tcp.h>
  63#include <linux/udp.h>
  64#include <linux/dccp.h>
  65#include <linux/quota.h>
  66#include <linux/un.h>           /* for Unix socket types */
  67#include <net/af_unix.h>        /* for Unix socket types */
  68#include <linux/parser.h>
  69#include <linux/nfs_mount.h>
  70#include <net/ipv6.h>
  71#include <linux/hugetlb.h>
  72#include <linux/personality.h>
  73#include <linux/sysctl.h>
  74#include <linux/audit.h>
  75#include <linux/string.h>
  76#include <linux/selinux.h>
  77#include <linux/mutex.h>
  78#include <linux/posix-timers.h>
  79
  80#include "avc.h"
  81#include "objsec.h"
  82#include "netif.h"
  83#include "netnode.h"
  84#include "netport.h"
  85#include "xfrm.h"
  86#include "netlabel.h"
  87#include "audit.h"
  88
  89#define XATTR_SELINUX_SUFFIX "selinux"
  90#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
  91
  92#define NUM_SEL_MNT_OPTS 5
  93
  94extern unsigned int policydb_loaded_version;
  95extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
  96extern struct security_operations *security_ops;
  97
  98/* SECMARK reference count */
  99atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
 100
 101#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 102int selinux_enforcing;
 103
 104static int __init enforcing_setup(char *str)
 105{
 106        unsigned long enforcing;
 107        if (!strict_strtoul(str, 0, &enforcing))
 108                selinux_enforcing = enforcing ? 1 : 0;
 109        return 1;
 110}
 111__setup("enforcing=", enforcing_setup);
 112#endif
 113
 114#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
 115int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
 116
 117static int __init selinux_enabled_setup(char *str)
 118{
 119        unsigned long enabled;
 120        if (!strict_strtoul(str, 0, &enabled))
 121                selinux_enabled = enabled ? 1 : 0;
 122        return 1;
 123}
 124__setup("selinux=", selinux_enabled_setup);
 125#else
 126int selinux_enabled = 1;
 127#endif
 128
 129
 130/*
 131 * Minimal support for a secondary security module,
 132 * just to allow the use of the capability module.
 133 */
 134static struct security_operations *secondary_ops;
 135
 136/* Lists of inode and superblock security structures initialized
 137   before the policy was loaded. */
 138static LIST_HEAD(superblock_security_head);
 139static DEFINE_SPINLOCK(sb_security_lock);
 140
 141static struct kmem_cache *sel_inode_cache;
 142
 143/**
 144 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
 145 *
 146 * Description:
 147 * This function checks the SECMARK reference counter to see if any SECMARK
 148 * targets are currently configured, if the reference counter is greater than
 149 * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
 150 * enabled, false (0) if SECMARK is disabled.
 151 *
 152 */
 153static int selinux_secmark_enabled(void)
 154{
 155        return (atomic_read(&selinux_secmark_refcount) > 0);
 156}
 157
 158/*
 159 * initialise the security for the init task
 160 */
 161static void cred_init_security(void)
 162{
 163        struct cred *cred = (struct cred *) current->real_cred;
 164        struct task_security_struct *tsec;
 165
 166        tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
 167        if (!tsec)
 168                panic("SELinux:  Failed to initialize initial task.\n");
 169
 170        tsec->osid = tsec->sid = SECINITSID_KERNEL;
 171        cred->security = tsec;
 172}
 173
 174/*
 175 * get the security ID of a set of credentials
 176 */
 177static inline u32 cred_sid(const struct cred *cred)
 178{
 179        const struct task_security_struct *tsec;
 180
 181        tsec = cred->security;
 182        return tsec->sid;
 183}
 184
 185/*
 186 * get the objective security ID of a task
 187 */
 188static inline u32 task_sid(const struct task_struct *task)
 189{
 190        u32 sid;
 191
 192        rcu_read_lock();
 193        sid = cred_sid(__task_cred(task));
 194        rcu_read_unlock();
 195        return sid;
 196}
 197
 198/*
 199 * get the subjective security ID of the current task
 200 */
 201static inline u32 current_sid(void)
 202{
 203        const struct task_security_struct *tsec = current_cred()->security;
 204
 205        return tsec->sid;
 206}
 207
 208/* Allocate and free functions for each kind of security blob. */
 209
 210static int inode_alloc_security(struct inode *inode)
 211{
 212        struct inode_security_struct *isec;
 213        u32 sid = current_sid();
 214
 215        isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
 216        if (!isec)
 217                return -ENOMEM;
 218
 219        mutex_init(&isec->lock);
 220        INIT_LIST_HEAD(&isec->list);
 221        isec->inode = inode;
 222        isec->sid = SECINITSID_UNLABELED;
 223        isec->sclass = SECCLASS_FILE;
 224        isec->task_sid = sid;
 225        inode->i_security = isec;
 226
 227        return 0;
 228}
 229
 230static void inode_free_security(struct inode *inode)
 231{
 232        struct inode_security_struct *isec = inode->i_security;
 233        struct superblock_security_struct *sbsec = inode->i_sb->s_security;
 234
 235        spin_lock(&sbsec->isec_lock);
 236        if (!list_empty(&isec->list))
 237                list_del_init(&isec->list);
 238        spin_unlock(&sbsec->isec_lock);
 239
 240        inode->i_security = NULL;
 241        kmem_cache_free(sel_inode_cache, isec);
 242}
 243
 244static int file_alloc_security(struct file *file)
 245{
 246        struct file_security_struct *fsec;
 247        u32 sid = current_sid();
 248
 249        fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
 250        if (!fsec)
 251                return -ENOMEM;
 252
 253        fsec->sid = sid;
 254        fsec->fown_sid = sid;
 255        file->f_security = fsec;
 256
 257        return 0;
 258}
 259
 260static void file_free_security(struct file *file)
 261{
 262        struct file_security_struct *fsec = file->f_security;
 263        file->f_security = NULL;
 264        kfree(fsec);
 265}
 266
 267static int superblock_alloc_security(struct super_block *sb)
 268{
 269        struct superblock_security_struct *sbsec;
 270
 271        sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
 272        if (!sbsec)
 273                return -ENOMEM;
 274
 275        mutex_init(&sbsec->lock);
 276        INIT_LIST_HEAD(&sbsec->list);
 277        INIT_LIST_HEAD(&sbsec->isec_head);
 278        spin_lock_init(&sbsec->isec_lock);
 279        sbsec->sb = sb;
 280        sbsec->sid = SECINITSID_UNLABELED;
 281        sbsec->def_sid = SECINITSID_FILE;
 282        sbsec->mntpoint_sid = SECINITSID_UNLABELED;
 283        sb->s_security = sbsec;
 284
 285        return 0;
 286}
 287
 288static void superblock_free_security(struct super_block *sb)
 289{
 290        struct superblock_security_struct *sbsec = sb->s_security;
 291
 292        spin_lock(&sb_security_lock);
 293        if (!list_empty(&sbsec->list))
 294                list_del_init(&sbsec->list);
 295        spin_unlock(&sb_security_lock);
 296
 297        sb->s_security = NULL;
 298        kfree(sbsec);
 299}
 300
 301static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
 302{
 303        struct sk_security_struct *ssec;
 304
 305        ssec = kzalloc(sizeof(*ssec), priority);
 306        if (!ssec)
 307                return -ENOMEM;
 308
 309        ssec->peer_sid = SECINITSID_UNLABELED;
 310        ssec->sid = SECINITSID_UNLABELED;
 311        sk->sk_security = ssec;
 312
 313        selinux_netlbl_sk_security_reset(ssec);
 314
 315        return 0;
 316}
 317
 318static void sk_free_security(struct sock *sk)
 319{
 320        struct sk_security_struct *ssec = sk->sk_security;
 321
 322        sk->sk_security = NULL;
 323        selinux_netlbl_sk_security_free(ssec);
 324        kfree(ssec);
 325}
 326
 327/* The security server must be initialized before
 328   any labeling or access decisions can be provided. */
 329extern int ss_initialized;
 330
 331/* The file system's label must be initialized prior to use. */
 332
 333static char *labeling_behaviors[6] = {
 334        "uses xattr",
 335        "uses transition SIDs",
 336        "uses task SIDs",
 337        "uses genfs_contexts",
 338        "not configured for labeling",
 339        "uses mountpoint labeling",
 340};
 341
 342static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
 343
 344static inline int inode_doinit(struct inode *inode)
 345{
 346        return inode_doinit_with_dentry(inode, NULL);
 347}
 348
 349enum {
 350        Opt_error = -1,
 351        Opt_context = 1,
 352        Opt_fscontext = 2,
 353        Opt_defcontext = 3,
 354        Opt_rootcontext = 4,
 355        Opt_labelsupport = 5,
 356};
 357
 358static const match_table_t tokens = {
 359        {Opt_context, CONTEXT_STR "%s"},
 360        {Opt_fscontext, FSCONTEXT_STR "%s"},
 361        {Opt_defcontext, DEFCONTEXT_STR "%s"},
 362        {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
 363        {Opt_labelsupport, LABELSUPP_STR},
 364        {Opt_error, NULL},
 365};
 366
 367#define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
 368
 369static int may_context_mount_sb_relabel(u32 sid,
 370                        struct superblock_security_struct *sbsec,
 371                        const struct cred *cred)
 372{
 373        const struct task_security_struct *tsec = cred->security;
 374        int rc;
 375
 376        rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
 377                          FILESYSTEM__RELABELFROM, NULL);
 378        if (rc)
 379                return rc;
 380
 381        rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
 382                          FILESYSTEM__RELABELTO, NULL);
 383        return rc;
 384}
 385
 386static int may_context_mount_inode_relabel(u32 sid,
 387                        struct superblock_security_struct *sbsec,
 388                        const struct cred *cred)
 389{
 390        const struct task_security_struct *tsec = cred->security;
 391        int rc;
 392        rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
 393                          FILESYSTEM__RELABELFROM, NULL);
 394        if (rc)
 395                return rc;
 396
 397        rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
 398                          FILESYSTEM__ASSOCIATE, NULL);
 399        return rc;
 400}
 401
 402static int sb_finish_set_opts(struct super_block *sb)
 403{
 404        struct superblock_security_struct *sbsec = sb->s_security;
 405        struct dentry *root = sb->s_root;
 406        struct inode *root_inode = root->d_inode;
 407        int rc = 0;
 408
 409        if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
 410                /* Make sure that the xattr handler exists and that no
 411                   error other than -ENODATA is returned by getxattr on
 412                   the root directory.  -ENODATA is ok, as this may be
 413                   the first boot of the SELinux kernel before we have
 414                   assigned xattr values to the filesystem. */
 415                if (!root_inode->i_op->getxattr) {
 416                        printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
 417                               "xattr support\n", sb->s_id, sb->s_type->name);
 418                        rc = -EOPNOTSUPP;
 419                        goto out;
 420                }
 421                rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
 422                if (rc < 0 && rc != -ENODATA) {
 423                        if (rc == -EOPNOTSUPP)
 424                                printk(KERN_WARNING "SELinux: (dev %s, type "
 425                                       "%s) has no security xattr handler\n",
 426                                       sb->s_id, sb->s_type->name);
 427                        else
 428                                printk(KERN_WARNING "SELinux: (dev %s, type "
 429                                       "%s) getxattr errno %d\n", sb->s_id,
 430                                       sb->s_type->name, -rc);
 431                        goto out;
 432                }
 433        }
 434
 435        sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
 436
 437        if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
 438                printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
 439                       sb->s_id, sb->s_type->name);
 440        else
 441                printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
 442                       sb->s_id, sb->s_type->name,
 443                       labeling_behaviors[sbsec->behavior-1]);
 444
 445        if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
 446            sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
 447            sbsec->behavior == SECURITY_FS_USE_NONE ||
 448            sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
 449                sbsec->flags &= ~SE_SBLABELSUPP;
 450
 451        /* Special handling for sysfs. Is genfs but also has setxattr handler*/
 452        if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
 453                sbsec->flags |= SE_SBLABELSUPP;
 454
 455        /* Initialize the root inode. */
 456        rc = inode_doinit_with_dentry(root_inode, root);
 457
 458        /* Initialize any other inodes associated with the superblock, e.g.
 459           inodes created prior to initial policy load or inodes created
 460           during get_sb by a pseudo filesystem that directly
 461           populates itself. */
 462        spin_lock(&sbsec->isec_lock);
 463next_inode:
 464        if (!list_empty(&sbsec->isec_head)) {
 465                struct inode_security_struct *isec =
 466                                list_entry(sbsec->isec_head.next,
 467                                           struct inode_security_struct, list);
 468                struct inode *inode = isec->inode;
 469                spin_unlock(&sbsec->isec_lock);
 470                inode = igrab(inode);
 471                if (inode) {
 472                        if (!IS_PRIVATE(inode))
 473                                inode_doinit(inode);
 474                        iput(inode);
 475                }
 476                spin_lock(&sbsec->isec_lock);
 477                list_del_init(&isec->list);
 478                goto next_inode;
 479        }
 480        spin_unlock(&sbsec->isec_lock);
 481out:
 482        return rc;
 483}
 484
 485/*
 486 * This function should allow an FS to ask what it's mount security
 487 * options were so it can use those later for submounts, displaying
 488 * mount options, or whatever.
 489 */
 490static int selinux_get_mnt_opts(const struct super_block *sb,
 491                                struct security_mnt_opts *opts)
 492{
 493        int rc = 0, i;
 494        struct superblock_security_struct *sbsec = sb->s_security;
 495        char *context = NULL;
 496        u32 len;
 497        char tmp;
 498
 499        security_init_mnt_opts(opts);
 500
 501        if (!(sbsec->flags & SE_SBINITIALIZED))
 502                return -EINVAL;
 503
 504        if (!ss_initialized)
 505                return -EINVAL;
 506
 507        tmp = sbsec->flags & SE_MNTMASK;
 508        /* count the number of mount options for this sb */
 509        for (i = 0; i < 8; i++) {
 510                if (tmp & 0x01)
 511                        opts->num_mnt_opts++;
 512                tmp >>= 1;
 513        }
 514        /* Check if the Label support flag is set */
 515        if (sbsec->flags & SE_SBLABELSUPP)
 516                opts->num_mnt_opts++;
 517
 518        opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
 519        if (!opts->mnt_opts) {
 520                rc = -ENOMEM;
 521                goto out_free;
 522        }
 523
 524        opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
 525        if (!opts->mnt_opts_flags) {
 526                rc = -ENOMEM;
 527                goto out_free;
 528        }
 529
 530        i = 0;
 531        if (sbsec->flags & FSCONTEXT_MNT) {
 532                rc = security_sid_to_context(sbsec->sid, &context, &len);
 533                if (rc)
 534                        goto out_free;
 535                opts->mnt_opts[i] = context;
 536                opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
 537        }
 538        if (sbsec->flags & CONTEXT_MNT) {
 539                rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
 540                if (rc)
 541                        goto out_free;
 542                opts->mnt_opts[i] = context;
 543                opts->mnt_opts_flags[i++] = CONTEXT_MNT;
 544        }
 545        if (sbsec->flags & DEFCONTEXT_MNT) {
 546                rc = security_sid_to_context(sbsec->def_sid, &context, &len);
 547                if (rc)
 548                        goto out_free;
 549                opts->mnt_opts[i] = context;
 550                opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
 551        }
 552        if (sbsec->flags & ROOTCONTEXT_MNT) {
 553                struct inode *root = sbsec->sb->s_root->d_inode;
 554                struct inode_security_struct *isec = root->i_security;
 555
 556                rc = security_sid_to_context(isec->sid, &context, &len);
 557                if (rc)
 558                        goto out_free;
 559                opts->mnt_opts[i] = context;
 560                opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
 561        }
 562        if (sbsec->flags & SE_SBLABELSUPP) {
 563                opts->mnt_opts[i] = NULL;
 564                opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
 565        }
 566
 567        BUG_ON(i != opts->num_mnt_opts);
 568
 569        return 0;
 570
 571out_free:
 572        security_free_mnt_opts(opts);
 573        return rc;
 574}
 575
 576static int bad_option(struct superblock_security_struct *sbsec, char flag,
 577                      u32 old_sid, u32 new_sid)
 578{
 579        char mnt_flags = sbsec->flags & SE_MNTMASK;
 580
 581        /* check if the old mount command had the same options */
 582        if (sbsec->flags & SE_SBINITIALIZED)
 583                if (!(sbsec->flags & flag) ||
 584                    (old_sid != new_sid))
 585                        return 1;
 586
 587        /* check if we were passed the same options twice,
 588         * aka someone passed context=a,context=b
 589         */
 590        if (!(sbsec->flags & SE_SBINITIALIZED))
 591                if (mnt_flags & flag)
 592                        return 1;
 593        return 0;
 594}
 595
 596/*
 597 * Allow filesystems with binary mount data to explicitly set mount point
 598 * labeling information.
 599 */
 600static int selinux_set_mnt_opts(struct super_block *sb,
 601                                struct security_mnt_opts *opts)
 602{
 603        const struct cred *cred = current_cred();
 604        int rc = 0, i;
 605        struct superblock_security_struct *sbsec = sb->s_security;
 606        const char *name = sb->s_type->name;
 607        struct inode *inode = sbsec->sb->s_root->d_inode;
 608        struct inode_security_struct *root_isec = inode->i_security;
 609        u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
 610        u32 defcontext_sid = 0;
 611        char **mount_options = opts->mnt_opts;
 612        int *flags = opts->mnt_opts_flags;
 613        int num_opts = opts->num_mnt_opts;
 614
 615        mutex_lock(&sbsec->lock);
 616
 617        if (!ss_initialized) {
 618                if (!num_opts) {
 619                        /* Defer initialization until selinux_complete_init,
 620                           after the initial policy is loaded and the security
 621                           server is ready to handle calls. */
 622                        spin_lock(&sb_security_lock);
 623                        if (list_empty(&sbsec->list))
 624                                list_add(&sbsec->list, &superblock_security_head);
 625                        spin_unlock(&sb_security_lock);
 626                        goto out;
 627                }
 628                rc = -EINVAL;
 629                printk(KERN_WARNING "SELinux: Unable to set superblock options "
 630                        "before the security server is initialized\n");
 631                goto out;
 632        }
 633
 634        /*
 635         * Binary mount data FS will come through this function twice.  Once
 636         * from an explicit call and once from the generic calls from the vfs.
 637         * Since the generic VFS calls will not contain any security mount data
 638         * we need to skip the double mount verification.
 639         *
 640         * This does open a hole in which we will not notice if the first
 641         * mount using this sb set explict options and a second mount using
 642         * this sb does not set any security options.  (The first options
 643         * will be used for both mounts)
 644         */
 645        if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
 646            && (num_opts == 0))
 647                goto out;
 648
 649        /*
 650         * parse the mount options, check if they are valid sids.
 651         * also check if someone is trying to mount the same sb more
 652         * than once with different security options.
 653         */
 654        for (i = 0; i < num_opts; i++) {
 655                u32 sid;
 656
 657                if (flags[i] == SE_SBLABELSUPP)
 658                        continue;
 659                rc = security_context_to_sid(mount_options[i],
 660                                             strlen(mount_options[i]), &sid);
 661                if (rc) {
 662                        printk(KERN_WARNING "SELinux: security_context_to_sid"
 663                               "(%s) failed for (dev %s, type %s) errno=%d\n",
 664                               mount_options[i], sb->s_id, name, rc);
 665                        goto out;
 666                }
 667                switch (flags[i]) {
 668                case FSCONTEXT_MNT:
 669                        fscontext_sid = sid;
 670
 671                        if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
 672                                        fscontext_sid))
 673                                goto out_double_mount;
 674
 675                        sbsec->flags |= FSCONTEXT_MNT;
 676                        break;
 677                case CONTEXT_MNT:
 678                        context_sid = sid;
 679
 680                        if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
 681                                        context_sid))
 682                                goto out_double_mount;
 683
 684                        sbsec->flags |= CONTEXT_MNT;
 685                        break;
 686                case ROOTCONTEXT_MNT:
 687                        rootcontext_sid = sid;
 688
 689                        if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
 690                                        rootcontext_sid))
 691                                goto out_double_mount;
 692
 693                        sbsec->flags |= ROOTCONTEXT_MNT;
 694
 695                        break;
 696                case DEFCONTEXT_MNT:
 697                        defcontext_sid = sid;
 698
 699                        if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
 700                                        defcontext_sid))
 701                                goto out_double_mount;
 702
 703                        sbsec->flags |= DEFCONTEXT_MNT;
 704
 705                        break;
 706                default:
 707                        rc = -EINVAL;
 708                        goto out;
 709                }
 710        }
 711
 712        if (sbsec->flags & SE_SBINITIALIZED) {
 713                /* previously mounted with options, but not on this attempt? */
 714                if ((sbsec->flags & SE_MNTMASK) && !num_opts)
 715                        goto out_double_mount;
 716                rc = 0;
 717                goto out;
 718        }
 719
 720        if (strcmp(sb->s_type->name, "proc") == 0)
 721                sbsec->flags |= SE_SBPROC;
 722
 723        /* Determine the labeling behavior to use for this filesystem type. */
 724        rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
 725        if (rc) {
 726                printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
 727                       __func__, sb->s_type->name, rc);
 728                goto out;
 729        }
 730
 731        /* sets the context of the superblock for the fs being mounted. */
 732        if (fscontext_sid) {
 733                rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
 734                if (rc)
 735                        goto out;
 736
 737                sbsec->sid = fscontext_sid;
 738        }
 739
 740        /*
 741         * Switch to using mount point labeling behavior.
 742         * sets the label used on all file below the mountpoint, and will set
 743         * the superblock context if not already set.
 744         */
 745        if (context_sid) {
 746                if (!fscontext_sid) {
 747                        rc = may_context_mount_sb_relabel(context_sid, sbsec,
 748                                                          cred);
 749                        if (rc)
 750                                goto out;
 751                        sbsec->sid = context_sid;
 752                } else {
 753                        rc = may_context_mount_inode_relabel(context_sid, sbsec,
 754                                                             cred);
 755                        if (rc)
 756                                goto out;
 757                }
 758                if (!rootcontext_sid)
 759                        rootcontext_sid = context_sid;
 760
 761                sbsec->mntpoint_sid = context_sid;
 762                sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
 763        }
 764
 765        if (rootcontext_sid) {
 766                rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
 767                                                     cred);
 768                if (rc)
 769                        goto out;
 770
 771                root_isec->sid = rootcontext_sid;
 772                root_isec->initialized = 1;
 773        }
 774
 775        if (defcontext_sid) {
 776                if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
 777                        rc = -EINVAL;
 778                        printk(KERN_WARNING "SELinux: defcontext option is "
 779                               "invalid for this filesystem type\n");
 780                        goto out;
 781                }
 782
 783                if (defcontext_sid != sbsec->def_sid) {
 784                        rc = may_context_mount_inode_relabel(defcontext_sid,
 785                                                             sbsec, cred);
 786                        if (rc)
 787                                goto out;
 788                }
 789
 790                sbsec->def_sid = defcontext_sid;
 791        }
 792
 793        rc = sb_finish_set_opts(sb);
 794out:
 795        mutex_unlock(&sbsec->lock);
 796        return rc;
 797out_double_mount:
 798        rc = -EINVAL;
 799        printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
 800               "security settings for (dev %s, type %s)\n", sb->s_id, name);
 801        goto out;
 802}
 803
 804static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
 805                                        struct super_block *newsb)
 806{
 807        const struct superblock_security_struct *oldsbsec = oldsb->s_security;
 808        struct superblock_security_struct *newsbsec = newsb->s_security;
 809
 810        int set_fscontext =     (oldsbsec->flags & FSCONTEXT_MNT);
 811        int set_context =       (oldsbsec->flags & CONTEXT_MNT);
 812        int set_rootcontext =   (oldsbsec->flags & ROOTCONTEXT_MNT);
 813
 814        /*
 815         * if the parent was able to be mounted it clearly had no special lsm
 816         * mount options.  thus we can safely put this sb on the list and deal
 817         * with it later
 818         */
 819        if (!ss_initialized) {
 820                spin_lock(&sb_security_lock);
 821                if (list_empty(&newsbsec->list))
 822                        list_add(&newsbsec->list, &superblock_security_head);
 823                spin_unlock(&sb_security_lock);
 824                return;
 825        }
 826
 827        /* how can we clone if the old one wasn't set up?? */
 828        BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
 829
 830        /* if fs is reusing a sb, just let its options stand... */
 831        if (newsbsec->flags & SE_SBINITIALIZED)
 832                return;
 833
 834        mutex_lock(&newsbsec->lock);
 835
 836        newsbsec->flags = oldsbsec->flags;
 837
 838        newsbsec->sid = oldsbsec->sid;
 839        newsbsec->def_sid = oldsbsec->def_sid;
 840        newsbsec->behavior = oldsbsec->behavior;
 841
 842        if (set_context) {
 843                u32 sid = oldsbsec->mntpoint_sid;
 844
 845                if (!set_fscontext)
 846                        newsbsec->sid = sid;
 847                if (!set_rootcontext) {
 848                        struct inode *newinode = newsb->s_root->d_inode;
 849                        struct inode_security_struct *newisec = newinode->i_security;
 850                        newisec->sid = sid;
 851                }
 852                newsbsec->mntpoint_sid = sid;
 853        }
 854        if (set_rootcontext) {
 855                const struct inode *oldinode = oldsb->s_root->d_inode;
 856                const struct inode_security_struct *oldisec = oldinode->i_security;
 857                struct inode *newinode = newsb->s_root->d_inode;
 858                struct inode_security_struct *newisec = newinode->i_security;
 859
 860                newisec->sid = oldisec->sid;
 861        }
 862
 863        sb_finish_set_opts(newsb);
 864        mutex_unlock(&newsbsec->lock);
 865}
 866
 867static int selinux_parse_opts_str(char *options,
 868                                  struct security_mnt_opts *opts)
 869{
 870        char *p;
 871        char *context = NULL, *defcontext = NULL;
 872        char *fscontext = NULL, *rootcontext = NULL;
 873        int rc, num_mnt_opts = 0;
 874
 875        opts->num_mnt_opts = 0;
 876
 877        /* Standard string-based options. */
 878        while ((p = strsep(&options, "|")) != NULL) {
 879                int token;
 880                substring_t args[MAX_OPT_ARGS];
 881
 882                if (!*p)
 883                        continue;
 884
 885                token = match_token(p, tokens, args);
 886
 887                switch (token) {
 888                case Opt_context:
 889                        if (context || defcontext) {
 890                                rc = -EINVAL;
 891                                printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 892                                goto out_err;
 893                        }
 894                        context = match_strdup(&args[0]);
 895                        if (!context) {
 896                                rc = -ENOMEM;
 897                                goto out_err;
 898                        }
 899                        break;
 900
 901                case Opt_fscontext:
 902                        if (fscontext) {
 903                                rc = -EINVAL;
 904                                printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 905                                goto out_err;
 906                        }
 907                        fscontext = match_strdup(&args[0]);
 908                        if (!fscontext) {
 909                                rc = -ENOMEM;
 910                                goto out_err;
 911                        }
 912                        break;
 913
 914                case Opt_rootcontext:
 915                        if (rootcontext) {
 916                                rc = -EINVAL;
 917                                printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 918                                goto out_err;
 919                        }
 920                        rootcontext = match_strdup(&args[0]);
 921                        if (!rootcontext) {
 922                                rc = -ENOMEM;
 923                                goto out_err;
 924                        }
 925                        break;
 926
 927                case Opt_defcontext:
 928                        if (context || defcontext) {
 929                                rc = -EINVAL;
 930                                printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 931                                goto out_err;
 932                        }
 933                        defcontext = match_strdup(&args[0]);
 934                        if (!defcontext) {
 935                                rc = -ENOMEM;
 936                                goto out_err;
 937                        }
 938                        break;
 939                case Opt_labelsupport:
 940                        break;
 941                default:
 942                        rc = -EINVAL;
 943                        printk(KERN_WARNING "SELinux:  unknown mount option\n");
 944                        goto out_err;
 945
 946                }
 947        }
 948
 949        rc = -ENOMEM;
 950        opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
 951        if (!opts->mnt_opts)
 952                goto out_err;
 953
 954        opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
 955        if (!opts->mnt_opts_flags) {
 956                kfree(opts->mnt_opts);
 957                goto out_err;
 958        }
 959
 960        if (fscontext) {
 961                opts->mnt_opts[num_mnt_opts] = fscontext;
 962                opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
 963        }
 964        if (context) {
 965                opts->mnt_opts[num_mnt_opts] = context;
 966                opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
 967        }
 968        if (rootcontext) {
 969                opts->mnt_opts[num_mnt_opts] = rootcontext;
 970                opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
 971        }
 972        if (defcontext) {
 973                opts->mnt_opts[num_mnt_opts] = defcontext;
 974                opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
 975        }
 976
 977        opts->num_mnt_opts = num_mnt_opts;
 978        return 0;
 979
 980out_err:
 981        kfree(context);
 982        kfree(defcontext);
 983        kfree(fscontext);
 984        kfree(rootcontext);
 985        return rc;
 986}
 987/*
 988 * string mount options parsing and call set the sbsec
 989 */
 990static int superblock_doinit(struct super_block *sb, void *data)
 991{
 992        int rc = 0;
 993        char *options = data;
 994        struct security_mnt_opts opts;
 995
 996        security_init_mnt_opts(&opts);
 997
 998        if (!data)
 999                goto out;
1000
1001        BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
1002
1003        rc = selinux_parse_opts_str(options, &opts);
1004        if (rc)
1005                goto out_err;
1006
1007out:
1008        rc = selinux_set_mnt_opts(sb, &opts);
1009
1010out_err:
1011        security_free_mnt_opts(&opts);
1012        return rc;
1013}
1014
1015static void selinux_write_opts(struct seq_file *m,
1016                               struct security_mnt_opts *opts)
1017{
1018        int i;
1019        char *prefix;
1020
1021        for (i = 0; i < opts->num_mnt_opts; i++) {
1022                char *has_comma;
1023
1024                if (opts->mnt_opts[i])
1025                        has_comma = strchr(opts->mnt_opts[i], ',');
1026                else
1027                        has_comma = NULL;
1028
1029                switch (opts->mnt_opts_flags[i]) {
1030                case CONTEXT_MNT:
1031                        prefix = CONTEXT_STR;
1032                        break;
1033                case FSCONTEXT_MNT:
1034                        prefix = FSCONTEXT_STR;
1035                        break;
1036                case ROOTCONTEXT_MNT:
1037                        prefix = ROOTCONTEXT_STR;
1038                        break;
1039                case DEFCONTEXT_MNT:
1040                        prefix = DEFCONTEXT_STR;
1041                        break;
1042                case SE_SBLABELSUPP:
1043                        seq_putc(m, ',');
1044                        seq_puts(m, LABELSUPP_STR);
1045                        continue;
1046                default:
1047                        BUG();
1048                };
1049                /* we need a comma before each option */
1050                seq_putc(m, ',');
1051                seq_puts(m, prefix);
1052                if (has_comma)
1053                        seq_putc(m, '\"');
1054                seq_puts(m, opts->mnt_opts[i]);
1055                if (has_comma)
1056                        seq_putc(m, '\"');
1057        }
1058}
1059
1060static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1061{
1062        struct security_mnt_opts opts;
1063        int rc;
1064
1065        rc = selinux_get_mnt_opts(sb, &opts);
1066        if (rc) {
1067                /* before policy load we may get EINVAL, don't show anything */
1068                if (rc == -EINVAL)
1069                        rc = 0;
1070                return rc;
1071        }
1072
1073        selinux_write_opts(m, &opts);
1074
1075        security_free_mnt_opts(&opts);
1076
1077        return rc;
1078}
1079
1080static inline u16 inode_mode_to_security_class(umode_t mode)
1081{
1082        switch (mode & S_IFMT) {
1083        case S_IFSOCK:
1084                return SECCLASS_SOCK_FILE;
1085        case S_IFLNK:
1086                return SECCLASS_LNK_FILE;
1087        case S_IFREG:
1088                return SECCLASS_FILE;
1089        case S_IFBLK:
1090                return SECCLASS_BLK_FILE;
1091        case S_IFDIR:
1092                return SECCLASS_DIR;
1093        case S_IFCHR:
1094                return SECCLASS_CHR_FILE;
1095        case S_IFIFO:
1096                return SECCLASS_FIFO_FILE;
1097
1098        }
1099
1100        return SECCLASS_FILE;
1101}
1102
1103static inline int default_protocol_stream(int protocol)
1104{
1105        return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1106}
1107
1108static inline int default_protocol_dgram(int protocol)
1109{
1110        return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1111}
1112
1113static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1114{
1115        switch (family) {
1116        case PF_UNIX:
1117                switch (type) {
1118                case SOCK_STREAM:
1119                case SOCK_SEQPACKET:
1120                        return SECCLASS_UNIX_STREAM_SOCKET;
1121                case SOCK_DGRAM:
1122                        return SECCLASS_UNIX_DGRAM_SOCKET;
1123                }
1124                break;
1125        case PF_INET:
1126        case PF_INET6:
1127                switch (type) {
1128                case SOCK_STREAM:
1129                        if (default_protocol_stream(protocol))
1130                                return SECCLASS_TCP_SOCKET;
1131                        else
1132                                return SECCLASS_RAWIP_SOCKET;
1133                case SOCK_DGRAM:
1134                        if (default_protocol_dgram(protocol))
1135                                return SECCLASS_UDP_SOCKET;
1136                        else
1137                                return SECCLASS_RAWIP_SOCKET;
1138                case SOCK_DCCP:
1139                        return SECCLASS_DCCP_SOCKET;
1140                default:
1141                        return SECCLASS_RAWIP_SOCKET;
1142                }
1143                break;
1144        case PF_NETLINK:
1145                switch (protocol) {
1146                case NETLINK_ROUTE:
1147                        return SECCLASS_NETLINK_ROUTE_SOCKET;
1148                case NETLINK_FIREWALL:
1149                        return SECCLASS_NETLINK_FIREWALL_SOCKET;
1150                case NETLINK_INET_DIAG:
1151                        return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1152                case NETLINK_NFLOG:
1153                        return SECCLASS_NETLINK_NFLOG_SOCKET;
1154                case NETLINK_XFRM:
1155                        return SECCLASS_NETLINK_XFRM_SOCKET;
1156                case NETLINK_SELINUX:
1157                        return SECCLASS_NETLINK_SELINUX_SOCKET;
1158                case NETLINK_AUDIT:
1159                        return SECCLASS_NETLINK_AUDIT_SOCKET;
1160                case NETLINK_IP6_FW:
1161                        return SECCLASS_NETLINK_IP6FW_SOCKET;
1162                case NETLINK_DNRTMSG:
1163                        return SECCLASS_NETLINK_DNRT_SOCKET;
1164                case NETLINK_KOBJECT_UEVENT:
1165                        return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1166                default:
1167                        return SECCLASS_NETLINK_SOCKET;
1168                }
1169        case PF_PACKET:
1170                return SECCLASS_PACKET_SOCKET;
1171        case PF_KEY:
1172                return SECCLASS_KEY_SOCKET;
1173        case PF_APPLETALK:
1174                return SECCLASS_APPLETALK_SOCKET;
1175        }
1176
1177        return SECCLASS_SOCKET;
1178}
1179
1180#ifdef CONFIG_PROC_FS
1181static int selinux_proc_get_sid(struct proc_dir_entry *de,
1182                                u16 tclass,
1183                                u32 *sid)
1184{
1185        int buflen, rc;
1186        char *buffer, *path, *end;
1187
1188        buffer = (char *)__get_free_page(GFP_KERNEL);
1189        if (!buffer)
1190                return -ENOMEM;
1191
1192        buflen = PAGE_SIZE;
1193        end = buffer+buflen;
1194        *--end = '\0';
1195        buflen--;
1196        path = end-1;
1197        *path = '/';
1198        while (de && de != de->parent) {
1199                buflen -= de->namelen + 1;
1200                if (buflen < 0)
1201                        break;
1202                end -= de->namelen;
1203                memcpy(end, de->name, de->namelen);
1204                *--end = '/';
1205                path = end;
1206                de = de->parent;
1207        }
1208        rc = security_genfs_sid("proc", path, tclass, sid);
1209        free_page((unsigned long)buffer);
1210        return rc;
1211}
1212#else
1213static int selinux_proc_get_sid(struct proc_dir_entry *de,
1214                                u16 tclass,
1215                                u32 *sid)
1216{
1217        return -EINVAL;
1218}
1219#endif
1220
1221/* The inode's security attributes must be initialized before first use. */
1222static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1223{
1224        struct superblock_security_struct *sbsec = NULL;
1225        struct inode_security_struct *isec = inode->i_security;
1226        u32 sid;
1227        struct dentry *dentry;
1228#define INITCONTEXTLEN 255
1229        char *context = NULL;
1230        unsigned len = 0;
1231        int rc = 0;
1232
1233        if (isec->initialized)
1234                goto out;
1235
1236        mutex_lock(&isec->lock);
1237        if (isec->initialized)
1238                goto out_unlock;
1239
1240        sbsec = inode->i_sb->s_security;
1241        if (!(sbsec->flags & SE_SBINITIALIZED)) {
1242                /* Defer initialization until selinux_complete_init,
1243                   after the initial policy is loaded and the security
1244                   server is ready to handle calls. */
1245                spin_lock(&sbsec->isec_lock);
1246                if (list_empty(&isec->list))
1247                        list_add(&isec->list, &sbsec->isec_head);
1248                spin_unlock(&sbsec->isec_lock);
1249                goto out_unlock;
1250        }
1251
1252        switch (sbsec->behavior) {
1253        case SECURITY_FS_USE_XATTR:
1254                if (!inode->i_op->getxattr) {
1255                        isec->sid = sbsec->def_sid;
1256                        break;
1257                }
1258
1259                /* Need a dentry, since the xattr API requires one.
1260                   Life would be simpler if we could just pass the inode. */
1261                if (opt_dentry) {
1262                        /* Called from d_instantiate or d_splice_alias. */
1263                        dentry = dget(opt_dentry);
1264                } else {
1265                        /* Called from selinux_complete_init, try to find a dentry. */
1266                        dentry = d_find_alias(inode);
1267                }
1268                if (!dentry) {
1269                        /*
1270                         * this is can be hit on boot when a file is accessed
1271                         * before the policy is loaded.  When we load policy we
1272                         * may find inodes that have no dentry on the
1273                         * sbsec->isec_head list.  No reason to complain as these
1274                         * will get fixed up the next time we go through
1275                         * inode_doinit with a dentry, before these inodes could
1276                         * be used again by userspace.
1277                         */
1278                        goto out_unlock;
1279                }
1280
1281                len = INITCONTEXTLEN;
1282                context = kmalloc(len+1, GFP_NOFS);
1283                if (!context) {
1284                        rc = -ENOMEM;
1285                        dput(dentry);
1286                        goto out_unlock;
1287                }
1288                context[len] = '\0';
1289                rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1290                                           context, len);
1291                if (rc == -ERANGE) {
1292                        kfree(context);
1293
1294                        /* Need a larger buffer.  Query for the right size. */
1295                        rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1296                                                   NULL, 0);
1297                        if (rc < 0) {
1298                                dput(dentry);
1299                                goto out_unlock;
1300                        }
1301                        len = rc;
1302                        context = kmalloc(len+1, GFP_NOFS);
1303                        if (!context) {
1304                                rc = -ENOMEM;
1305                                dput(dentry);
1306                                goto out_unlock;
1307                        }
1308                        context[len] = '\0';
1309                        rc = inode->i_op->getxattr(dentry,
1310                                                   XATTR_NAME_SELINUX,
1311                                                   context, len);
1312                }
1313                dput(dentry);
1314                if (rc < 0) {
1315                        if (rc != -ENODATA) {
1316                                printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1317                                       "%d for dev=%s ino=%ld\n", __func__,
1318                                       -rc, inode->i_sb->s_id, inode->i_ino);
1319                                kfree(context);
1320                                goto out_unlock;
1321                        }
1322                        /* Map ENODATA to the default file SID */
1323                        sid = sbsec->def_sid;
1324                        rc = 0;
1325                } else {
1326                        rc = security_context_to_sid_default(context, rc, &sid,
1327                                                             sbsec->def_sid,
1328                                                             GFP_NOFS);
1329                        if (rc) {
1330                                char *dev = inode->i_sb->s_id;
1331                                unsigned long ino = inode->i_ino;
1332
1333                                if (rc == -EINVAL) {
1334                                        if (printk_ratelimit())
1335                                                printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1336                                                        "context=%s.  This indicates you may need to relabel the inode or the "
1337                                                        "filesystem in question.\n", ino, dev, context);
1338                                } else {
1339                                        printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
1340                                               "returned %d for dev=%s ino=%ld\n",
1341                                               __func__, context, -rc, dev, ino);
1342                                }
1343                                kfree(context);
1344                                /* Leave with the unlabeled SID */
1345                                rc = 0;
1346                                break;
1347                        }
1348                }
1349                kfree(context);
1350                isec->sid = sid;
1351                break;
1352        case SECURITY_FS_USE_TASK:
1353                isec->sid = isec->task_sid;
1354                break;
1355        case SECURITY_FS_USE_TRANS:
1356                /* Default to the fs SID. */
1357                isec->sid = sbsec->sid;
1358
1359                /* Try to obtain a transition SID. */
1360                isec->sclass = inode_mode_to_security_class(inode->i_mode);
1361                rc = security_transition_sid(isec->task_sid,
1362                                             sbsec->sid,
1363                                             isec->sclass,
1364                                             &sid);
1365                if (rc)
1366                        goto out_unlock;
1367                isec->sid = sid;
1368                break;
1369        case SECURITY_FS_USE_MNTPOINT:
1370                isec->sid = sbsec->mntpoint_sid;
1371                break;
1372        default:
1373                /* Default to the fs superblock SID. */
1374                isec->sid = sbsec->sid;
1375
1376                if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1377                        struct proc_inode *proci = PROC_I(inode);
1378                        if (proci->pde) {
1379                                isec->sclass = inode_mode_to_security_class(inode->i_mode);
1380                                rc = selinux_proc_get_sid(proci->pde,
1381                                                          isec->sclass,
1382                                                          &sid);
1383                                if (rc)
1384                                        goto out_unlock;
1385                                isec->sid = sid;
1386                        }
1387                }
1388                break;
1389        }
1390
1391        isec->initialized = 1;
1392
1393out_unlock:
1394        mutex_unlock(&isec->lock);
1395out:
1396        if (isec->sclass == SECCLASS_FILE)
1397                isec->sclass = inode_mode_to_security_class(inode->i_mode);
1398        return rc;
1399}
1400
1401/* Convert a Linux signal to an access vector. */
1402static inline u32 signal_to_av(int sig)
1403{
1404        u32 perm = 0;
1405
1406        switch (sig) {
1407        case SIGCHLD:
1408                /* Commonly granted from child to parent. */
1409                perm = PROCESS__SIGCHLD;
1410                break;
1411        case SIGKILL:
1412                /* Cannot be caught or ignored */
1413                perm = PROCESS__SIGKILL;
1414                break;
1415        case SIGSTOP:
1416                /* Cannot be caught or ignored */
1417                perm = PROCESS__SIGSTOP;
1418                break;
1419        default:
1420                /* All other signals. */
1421                perm = PROCESS__SIGNAL;
1422                break;
1423        }
1424
1425        return perm;
1426}
1427
1428/*
1429 * Check permission between a pair of credentials
1430 * fork check, ptrace check, etc.
1431 */
1432static int cred_has_perm(const struct cred *actor,
1433                         const struct cred *target,
1434                         u32 perms)
1435{
1436        u32 asid = cred_sid(actor), tsid = cred_sid(target);
1437
1438        return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1439}
1440
1441/*
1442 * Check permission between a pair of tasks, e.g. signal checks,
1443 * fork check, ptrace check, etc.
1444 * tsk1 is the actor and tsk2 is the target
1445 * - this uses the default subjective creds of tsk1
1446 */
1447static int task_has_perm(const struct task_struct *tsk1,
1448                         const struct task_struct *tsk2,
1449                         u32 perms)
1450{
1451        const struct task_security_struct *__tsec1, *__tsec2;
1452        u32 sid1, sid2;
1453
1454        rcu_read_lock();
1455        __tsec1 = __task_cred(tsk1)->security;  sid1 = __tsec1->sid;
1456        __tsec2 = __task_cred(tsk2)->security;  sid2 = __tsec2->sid;
1457        rcu_read_unlock();
1458        return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1459}
1460
1461/*
1462 * Check permission between current and another task, e.g. signal checks,
1463 * fork check, ptrace check, etc.
1464 * current is the actor and tsk2 is the target
1465 * - this uses current's subjective creds
1466 */
1467static int current_has_perm(const struct task_struct *tsk,
1468                            u32 perms)
1469{
1470        u32 sid, tsid;
1471
1472        sid = current_sid();
1473        tsid = task_sid(tsk);
1474        return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1475}
1476
1477#if CAP_LAST_CAP > 63
1478#error Fix SELinux to handle capabilities > 63.
1479#endif
1480
1481/* Check whether a task is allowed to use a capability. */
1482static int task_has_capability(struct task_struct *tsk,
1483                               const struct cred *cred,
1484                               int cap, int audit)
1485{
1486        struct common_audit_data ad;
1487        struct av_decision avd;
1488        u16 sclass;
1489        u32 sid = cred_sid(cred);
1490        u32 av = CAP_TO_MASK(cap);
1491        int rc;
1492
1493        COMMON_AUDIT_DATA_INIT(&ad, CAP);
1494        ad.tsk = tsk;
1495        ad.u.cap = cap;
1496
1497        switch (CAP_TO_INDEX(cap)) {
1498        case 0:
1499                sclass = SECCLASS_CAPABILITY;
1500                break;
1501        case 1:
1502                sclass = SECCLASS_CAPABILITY2;
1503                break;
1504        default:
1505                printk(KERN_ERR
1506                       "SELinux:  out of range capability %d\n", cap);
1507                BUG();
1508        }
1509
1510        rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1511        if (audit == SECURITY_CAP_AUDIT)
1512                avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1513        return rc;
1514}
1515
1516/* Check whether a task is allowed to use a system operation. */
1517static int task_has_system(struct task_struct *tsk,
1518                           u32 perms)
1519{
1520        u32 sid = task_sid(tsk);
1521
1522        return avc_has_perm(sid, SECINITSID_KERNEL,
1523                            SECCLASS_SYSTEM, perms, NULL);
1524}
1525
1526/* Check whether a task has a particular permission to an inode.
1527   The 'adp' parameter is optional and allows other audit
1528   data to be passed (e.g. the dentry). */
1529static int inode_has_perm(const struct cred *cred,
1530                          struct inode *inode,
1531                          u32 perms,
1532                          struct common_audit_data *adp)
1533{
1534        struct inode_security_struct *isec;
1535        struct common_audit_data ad;
1536        u32 sid;
1537
1538        validate_creds(cred);
1539
1540        if (unlikely(IS_PRIVATE(inode)))
1541                return 0;
1542
1543        sid = cred_sid(cred);
1544        isec = inode->i_security;
1545
1546        if (!adp) {
1547                adp = &ad;
1548                COMMON_AUDIT_DATA_INIT(&ad, FS);
1549                ad.u.fs.inode = inode;
1550        }
1551
1552        return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1553}
1554
1555/* Same as inode_has_perm, but pass explicit audit data containing
1556   the dentry to help the auditing code to more easily generate the
1557   pathname if needed. */
1558static inline int dentry_has_perm(const struct cred *cred,
1559                                  struct vfsmount *mnt,
1560                                  struct dentry *dentry,
1561                                  u32 av)
1562{
1563        struct inode *inode = dentry->d_inode;
1564        struct common_audit_data ad;
1565
1566        COMMON_AUDIT_DATA_INIT(&ad, FS);
1567        ad.u.fs.path.mnt = mnt;
1568        ad.u.fs.path.dentry = dentry;
1569        return inode_has_perm(cred, inode, av, &ad);
1570}
1571
1572/* Check whether a task can use an open file descriptor to
1573   access an inode in a given way.  Check access to the
1574   descriptor itself, and then use dentry_has_perm to
1575   check a particular permission to the file.
1576   Access to the descriptor is implicitly granted if it
1577   has the same SID as the process.  If av is zero, then
1578   access to the file is not checked, e.g. for cases
1579   where only the descriptor is affected like seek. */
1580static int file_has_perm(const struct cred *cred,
1581                         struct file *file,
1582                         u32 av)
1583{
1584        struct file_security_struct *fsec = file->f_security;
1585        struct inode *inode = file->f_path.dentry->d_inode;
1586        struct common_audit_data ad;
1587        u32 sid = cred_sid(cred);
1588        int rc;
1589
1590        COMMON_AUDIT_DATA_INIT(&ad, FS);
1591        ad.u.fs.path = file->f_path;
1592
1593        if (sid != fsec->sid) {
1594                rc = avc_has_perm(sid, fsec->sid,
1595                                  SECCLASS_FD,
1596                                  FD__USE,
1597                                  &ad);
1598                if (rc)
1599                        goto out;
1600        }
1601
1602        /* av is zero if only checking access to the descriptor. */
1603        rc = 0;
1604        if (av)
1605                rc = inode_has_perm(cred, inode, av, &ad);
1606
1607out:
1608        return rc;
1609}
1610
1611/* Check whether a task can create a file. */
1612static int may_create(struct inode *dir,
1613                      struct dentry *dentry,
1614                      u16 tclass)
1615{
1616        const struct cred *cred = current_cred();
1617        const struct task_security_struct *tsec = cred->security;
1618        struct inode_security_struct *dsec;
1619        struct superblock_security_struct *sbsec;
1620        u32 sid, newsid;
1621        struct common_audit_data ad;
1622        int rc;
1623
1624        dsec = dir->i_security;
1625        sbsec = dir->i_sb->s_security;
1626
1627        sid = tsec->sid;
1628        newsid = tsec->create_sid;
1629
1630        COMMON_AUDIT_DATA_INIT(&ad, FS);
1631        ad.u.fs.path.dentry = dentry;
1632
1633        rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1634                          DIR__ADD_NAME | DIR__SEARCH,
1635                          &ad);
1636        if (rc)
1637                return rc;
1638
1639        if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
1640                rc = security_transition_sid(sid, dsec->sid, tclass, &newsid);
1641                if (rc)
1642                        return rc;
1643        }
1644
1645        rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1646        if (rc)
1647                return rc;
1648
1649        return avc_has_perm(newsid, sbsec->sid,
1650                            SECCLASS_FILESYSTEM,
1651                            FILESYSTEM__ASSOCIATE, &ad);
1652}
1653
1654/* Check whether a task can create a key. */
1655static int may_create_key(u32 ksid,
1656                          struct task_struct *ctx)
1657{
1658        u32 sid = task_sid(ctx);
1659
1660        return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1661}
1662
1663#define MAY_LINK        0
1664#define MAY_UNLINK      1
1665#define MAY_RMDIR       2
1666
1667/* Check whether a task can link, unlink, or rmdir a file/directory. */
1668static int may_link(struct inode *dir,
1669                    struct dentry *dentry,
1670                    int kind)
1671
1672{
1673        struct inode_security_struct *dsec, *isec;
1674        struct common_audit_data ad;
1675        u32 sid = current_sid();
1676        u32 av;
1677        int rc;
1678
1679        dsec = dir->i_security;
1680        isec = dentry->d_inode->i_security;
1681
1682        COMMON_AUDIT_DATA_INIT(&ad, FS);
1683        ad.u.fs.path.dentry = dentry;
1684
1685        av = DIR__SEARCH;
1686        av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1687        rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1688        if (rc)
1689                return rc;
1690
1691        switch (kind) {
1692        case MAY_LINK:
1693                av = FILE__LINK;
1694                break;
1695        case MAY_UNLINK:
1696                av = FILE__UNLINK;
1697                break;
1698        case MAY_RMDIR:
1699                av = DIR__RMDIR;
1700                break;
1701        default:
1702                printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
1703                        __func__, kind);
1704                return 0;
1705        }
1706
1707        rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1708        return rc;
1709}
1710
1711static inline int may_rename(struct inode *old_dir,
1712                             struct dentry *old_dentry,
1713                             struct inode *new_dir,
1714                             struct dentry *new_dentry)
1715{
1716        struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1717        struct common_audit_data ad;
1718        u32 sid = current_sid();
1719        u32 av;
1720        int old_is_dir, new_is_dir;
1721        int rc;
1722
1723        old_dsec = old_dir->i_security;
1724        old_isec = old_dentry->d_inode->i_security;
1725        old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1726        new_dsec = new_dir->i_security;
1727
1728        COMMON_AUDIT_DATA_INIT(&ad, FS);
1729
1730        ad.u.fs.path.dentry = old_dentry;
1731        rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1732                          DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1733        if (rc)
1734                return rc;
1735        rc = avc_has_perm(sid, old_isec->sid,
1736                          old_isec->sclass, FILE__RENAME, &ad);
1737        if (rc)
1738                return rc;
1739        if (old_is_dir && new_dir != old_dir) {
1740                rc = avc_has_perm(sid, old_isec->sid,
1741                                  old_isec->sclass, DIR__REPARENT, &ad);
1742                if (rc)
1743                        return rc;
1744        }
1745
1746        ad.u.fs.path.dentry = new_dentry;
1747        av = DIR__ADD_NAME | DIR__SEARCH;
1748        if (new_dentry->d_inode)
1749                av |= DIR__REMOVE_NAME;
1750        rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1751        if (rc)
1752                return rc;
1753        if (new_dentry->d_inode) {
1754                new_isec = new_dentry->d_inode->i_security;
1755                new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1756                rc = avc_has_perm(sid, new_isec->sid,
1757                                  new_isec->sclass,
1758                                  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1759                if (rc)
1760                        return rc;
1761        }
1762
1763        return 0;
1764}
1765
1766/* Check whether a task can perform a filesystem operation. */
1767static int superblock_has_perm(const struct cred *cred,
1768                               struct super_block *sb,
1769                               u32 perms,
1770                               struct common_audit_data *ad)
1771{
1772        struct superblock_security_struct *sbsec;
1773        u32 sid = cred_sid(cred);
1774
1775        sbsec = sb->s_security;
1776        return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1777}
1778
1779/* Convert a Linux mode and permission mask to an access vector. */
1780static inline u32 file_mask_to_av(int mode, int mask)
1781{
1782        u32 av = 0;
1783
1784        if ((mode & S_IFMT) != S_IFDIR) {
1785                if (mask & MAY_EXEC)
1786                        av |= FILE__EXECUTE;
1787                if (mask & MAY_READ)
1788                        av |= FILE__READ;
1789
1790                if (mask & MAY_APPEND)
1791                        av |= FILE__APPEND;
1792                else if (mask & MAY_WRITE)
1793                        av |= FILE__WRITE;
1794
1795        } else {
1796                if (mask & MAY_EXEC)
1797                        av |= DIR__SEARCH;
1798                if (mask & MAY_WRITE)
1799                        av |= DIR__WRITE;
1800                if (mask & MAY_READ)
1801                        av |= DIR__READ;
1802        }
1803
1804        return av;
1805}
1806
1807/* Convert a Linux file to an access vector. */
1808static inline u32 file_to_av(struct file *file)
1809{
1810        u32 av = 0;
1811
1812        if (file->f_mode & FMODE_READ)
1813                av |= FILE__READ;
1814        if (file->f_mode & FMODE_WRITE) {
1815                if (file->f_flags & O_APPEND)
1816                        av |= FILE__APPEND;
1817                else
1818                        av |= FILE__WRITE;
1819        }
1820        if (!av) {
1821                /*
1822                 * Special file opened with flags 3 for ioctl-only use.
1823                 */
1824                av = FILE__IOCTL;
1825        }
1826
1827        return av;
1828}
1829
1830/*
1831 * Convert a file to an access vector and include the correct open
1832 * open permission.
1833 */
1834static inline u32 open_file_to_av(struct file *file)
1835{
1836        u32 av = file_to_av(file);
1837
1838        if (selinux_policycap_openperm) {
1839                mode_t mode = file->f_path.dentry->d_inode->i_mode;
1840                /*
1841                 * lnk files and socks do not really have an 'open'
1842                 */
1843                if (S_ISREG(mode))
1844                        av |= FILE__OPEN;
1845                else if (S_ISCHR(mode))
1846                        av |= CHR_FILE__OPEN;
1847                else if (S_ISBLK(mode))
1848                        av |= BLK_FILE__OPEN;
1849                else if (S_ISFIFO(mode))
1850                        av |= FIFO_FILE__OPEN;
1851                else if (S_ISDIR(mode))
1852                        av |= DIR__OPEN;
1853                else if (S_ISSOCK(mode))
1854                        av |= SOCK_FILE__OPEN;
1855                else
1856                        printk(KERN_ERR "SELinux: WARNING: inside %s with "
1857                                "unknown mode:%o\n", __func__, mode);
1858        }
1859        return av;
1860}
1861
1862/* Hook functions begin here. */
1863
1864static int selinux_ptrace_access_check(struct task_struct *child,
1865                                     unsigned int mode)
1866{
1867        int rc;
1868
1869        rc = cap_ptrace_access_check(child, mode);
1870        if (rc)
1871                return rc;
1872
1873        if (mode == PTRACE_MODE_READ) {
1874                u32 sid = current_sid();
1875                u32 csid = task_sid(child);
1876                return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1877        }
1878
1879        return current_has_perm(child, PROCESS__PTRACE);
1880}
1881
1882static int selinux_ptrace_traceme(struct task_struct *parent)
1883{
1884        int rc;
1885
1886        rc = cap_ptrace_traceme(parent);
1887        if (rc)
1888                return rc;
1889
1890        return task_has_perm(parent, current, PROCESS__PTRACE);
1891}
1892
1893static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1894                          kernel_cap_t *inheritable, kernel_cap_t *permitted)
1895{
1896        int error;
1897
1898        error = current_has_perm(target, PROCESS__GETCAP);
1899        if (error)
1900                return error;
1901
1902        return cap_capget(target, effective, inheritable, permitted);
1903}
1904
1905static int selinux_capset(struct cred *new, const struct cred *old,
1906                          const kernel_cap_t *effective,
1907                          const kernel_cap_t *inheritable,
1908                          const kernel_cap_t *permitted)
1909{
1910        int error;
1911
1912        error = cap_capset(new, old,
1913                                      effective, inheritable, permitted);
1914        if (error)
1915                return error;
1916
1917        return cred_has_perm(old, new, PROCESS__SETCAP);
1918}
1919
1920/*
1921 * (This comment used to live with the selinux_task_setuid hook,
1922 * which was removed).
1923 *
1924 * Since setuid only affects the current process, and since the SELinux
1925 * controls are not based on the Linux identity attributes, SELinux does not
1926 * need to control this operation.  However, SELinux does control the use of
1927 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1928 */
1929
1930static int selinux_capable(struct task_struct *tsk, const struct cred *cred,
1931                           int cap, int audit)
1932{
1933        int rc;
1934
1935        rc = cap_capable(tsk, cred, cap, audit);
1936        if (rc)
1937                return rc;
1938
1939        return task_has_capability(tsk, cred, cap, audit);
1940}
1941
1942static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
1943{
1944        int buflen, rc;
1945        char *buffer, *path, *end;
1946
1947        rc = -ENOMEM;
1948        buffer = (char *)__get_free_page(GFP_KERNEL);
1949        if (!buffer)
1950                goto out;
1951
1952        buflen = PAGE_SIZE;
1953        end = buffer+buflen;
1954        *--end = '\0';
1955        buflen--;
1956        path = end-1;
1957        *path = '/';
1958        while (table) {
1959                const char *name = table->procname;
1960                size_t namelen = strlen(name);
1961                buflen -= namelen + 1;
1962                if (buflen < 0)
1963                        goto out_free;
1964                end -= namelen;
1965                memcpy(end, name, namelen);
1966                *--end = '/';
1967                path = end;
1968                table = table->parent;
1969        }
1970        buflen -= 4;
1971        if (buflen < 0)
1972                goto out_free;
1973        end -= 4;
1974        memcpy(end, "/sys", 4);
1975        path = end;
1976        rc = security_genfs_sid("proc", path, tclass, sid);
1977out_free:
1978        free_page((unsigned long)buffer);
1979out:
1980        return rc;
1981}
1982
1983static int selinux_sysctl(ctl_table *table, int op)
1984{
1985        int error = 0;
1986        u32 av;
1987        u32 tsid, sid;
1988        int rc;
1989
1990        sid = current_sid();
1991
1992        rc = selinux_sysctl_get_sid(table, (op == 0001) ?
1993                                    SECCLASS_DIR : SECCLASS_FILE, &tsid);
1994        if (rc) {
1995                /* Default to the well-defined sysctl SID. */
1996                tsid = SECINITSID_SYSCTL;
1997        }
1998
1999        /* The op values are "defined" in sysctl.c, thereby creating
2000         * a bad coupling between this module and sysctl.c */
2001        if (op == 001) {
2002                error = avc_has_perm(sid, tsid,
2003                                     SECCLASS_DIR, DIR__SEARCH, NULL);
2004        } else {
2005                av = 0;
2006                if (op & 004)
2007                        av |= FILE__READ;
2008                if (op & 002)
2009                        av |= FILE__WRITE;
2010                if (av)
2011                        error = avc_has_perm(sid, tsid,
2012                                             SECCLASS_FILE, av, NULL);
2013        }
2014
2015        return error;
2016}
2017
2018static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
2019{
2020        const struct cred *cred = current_cred();
2021        int rc = 0;
2022
2023        if (!sb)
2024                return 0;
2025
2026        switch (cmds) {
2027        case Q_SYNC:
2028        case Q_QUOTAON:
2029        case Q_QUOTAOFF:
2030        case Q_SETINFO:
2031        case Q_SETQUOTA:
2032                rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2033                break;
2034        case Q_GETFMT:
2035        case Q_GETINFO:
2036        case Q_GETQUOTA:
2037                rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2038                break;
2039        default:
2040                rc = 0;  /* let the kernel handle invalid cmds */
2041                break;
2042        }
2043        return rc;
2044}
2045
2046static int selinux_quota_on(struct dentry *dentry)
2047{
2048        const struct cred *cred = current_cred();
2049
2050        return dentry_has_perm(cred, NULL, dentry, FILE__QUOTAON);
2051}
2052
2053static int selinux_syslog(int type)
2054{
2055        int rc;
2056
2057        rc = cap_syslog(type);
2058        if (rc)
2059                return rc;
2060
2061        switch (type) {
2062        case 3:         /* Read last kernel messages */
2063        case 10:        /* Return size of the log buffer */
2064                rc = task_has_system(current, SYSTEM__SYSLOG_READ);
2065                break;
2066        case 6:         /* Disable logging to console */
2067        case 7:         /* Enable logging to console */
2068        case 8:         /* Set level of messages printed to console */
2069                rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
2070                break;
2071        case 0:         /* Close log */
2072        case 1:         /* Open log */
2073        case 2:         /* Read from log */
2074        case 4:         /* Read/clear last kernel messages */
2075        case 5:         /* Clear ring buffer */
2076        default:
2077                rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
2078                break;
2079        }
2080        return rc;
2081}
2082
2083/*
2084 * Check that a process has enough memory to allocate a new virtual
2085 * mapping. 0 means there is enough memory for the allocation to
2086 * succeed and -ENOMEM implies there is not.
2087 *
2088 * Do not audit the selinux permission check, as this is applied to all
2089 * processes that allocate mappings.
2090 */
2091static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2092{
2093        int rc, cap_sys_admin = 0;
2094
2095        rc = selinux_capable(current, current_cred(), CAP_SYS_ADMIN,
2096                             SECURITY_CAP_NOAUDIT);
2097        if (rc == 0)
2098                cap_sys_admin = 1;
2099
2100        return __vm_enough_memory(mm, pages, cap_sys_admin);
2101}
2102
2103/* binprm security operations */
2104
2105static int selinux_bprm_set_creds(struct linux_binprm *bprm)
2106{
2107        const struct task_security_struct *old_tsec;
2108        struct task_security_struct *new_tsec;
2109        struct inode_security_struct *isec;
2110        struct common_audit_data ad;
2111        struct inode *inode = bprm->file->f_path.dentry->d_inode;
2112        int rc;
2113
2114        rc = cap_bprm_set_creds(bprm);
2115        if (rc)
2116                return rc;
2117
2118        /* SELinux context only depends on initial program or script and not
2119         * the script interpreter */
2120        if (bprm->cred_prepared)
2121                return 0;
2122
2123        old_tsec = current_security();
2124        new_tsec = bprm->cred->security;
2125        isec = inode->i_security;
2126
2127        /* Default to the current task SID. */
2128        new_tsec->sid = old_tsec->sid;
2129        new_tsec->osid = old_tsec->sid;
2130
2131        /* Reset fs, key, and sock SIDs on execve. */
2132        new_tsec->create_sid = 0;
2133        new_tsec->keycreate_sid = 0;
2134        new_tsec->sockcreate_sid = 0;
2135
2136        if (old_tsec->exec_sid) {
2137                new_tsec->sid = old_tsec->exec_sid;
2138                /* Reset exec SID on execve. */
2139                new_tsec->exec_sid = 0;
2140        } else {
2141                /* Check for a default transition on this program. */
2142                rc = security_transition_sid(old_tsec->sid, isec->sid,
2143                                             SECCLASS_PROCESS, &new_tsec->sid);
2144                if (rc)
2145                        return rc;
2146        }
2147
2148        COMMON_AUDIT_DATA_INIT(&ad, FS);
2149        ad.u.fs.path = bprm->file->f_path;
2150
2151        if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
2152                new_tsec->sid = old_tsec->sid;
2153
2154        if (new_tsec->sid == old_tsec->sid) {
2155                rc = avc_has_perm(old_tsec->sid, isec->sid,
2156                                  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2157                if (rc)
2158                        return rc;
2159        } else {
2160                /* Check permissions for the transition. */
2161                rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2162                                  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2163                if (rc)
2164                        return rc;
2165
2166                rc = avc_has_perm(new_tsec->sid, isec->sid,
2167                                  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2168                if (rc)
2169                        return rc;
2170
2171                /* Check for shared state */
2172                if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2173                        rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2174                                          SECCLASS_PROCESS, PROCESS__SHARE,
2175                                          NULL);
2176                        if (rc)
2177                                return -EPERM;
2178                }
2179
2180                /* Make sure that anyone attempting to ptrace over a task that
2181                 * changes its SID has the appropriate permit */
2182                if (bprm->unsafe &
2183                    (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2184                        struct task_struct *tracer;
2185                        struct task_security_struct *sec;
2186                        u32 ptsid = 0;
2187
2188                        rcu_read_lock();
2189                        tracer = tracehook_tracer_task(current);
2190                        if (likely(tracer != NULL)) {
2191                                sec = __task_cred(tracer)->security;
2192                                ptsid = sec->sid;
2193                        }
2194                        rcu_read_unlock();
2195
2196                        if (ptsid != 0) {
2197                                rc = avc_has_perm(ptsid, new_tsec->sid,
2198                                                  SECCLASS_PROCESS,
2199                                                  PROCESS__PTRACE, NULL);
2200                                if (rc)
2201                                        return -EPERM;
2202                        }
2203                }
2204
2205                /* Clear any possibly unsafe personality bits on exec: */
2206                bprm->per_clear |= PER_CLEAR_ON_SETID;
2207        }
2208
2209        return 0;
2210}
2211
2212static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2213{
2214        const struct cred *cred = current_cred();
2215        const struct task_security_struct *tsec = cred->security;
2216        u32 sid, osid;
2217        int atsecure = 0;
2218
2219        sid = tsec->sid;
2220        osid = tsec->osid;
2221
2222        if (osid != sid) {
2223                /* Enable secure mode for SIDs transitions unless
2224                   the noatsecure permission is granted between
2225                   the two SIDs, i.e. ahp returns 0. */
2226                atsecure = avc_has_perm(osid, sid,
2227                                        SECCLASS_PROCESS,
2228                                        PROCESS__NOATSECURE, NULL);
2229        }
2230
2231        return (atsecure || cap_bprm_secureexec(bprm));
2232}
2233
2234extern struct vfsmount *selinuxfs_mount;
2235extern struct dentry *selinux_null;
2236
2237/* Derived from fs/exec.c:flush_old_files. */
2238static inline void flush_unauthorized_files(const struct cred *cred,
2239                                            struct files_struct *files)
2240{
2241        struct common_audit_data ad;
2242        struct file *file, *devnull = NULL;
2243        struct tty_struct *tty;
2244        struct fdtable *fdt;
2245        long j = -1;
2246        int drop_tty = 0;
2247
2248        tty = get_current_tty();
2249        if (tty) {
2250                file_list_lock();
2251                if (!list_empty(&tty->tty_files)) {
2252                        struct inode *inode;
2253
2254                        /* Revalidate access to controlling tty.
2255                           Use inode_has_perm on the tty inode directly rather
2256                           than using file_has_perm, as this particular open
2257                           file may belong to another process and we are only
2258                           interested in the inode-based check here. */
2259                        file = list_first_entry(&tty->tty_files, struct file, f_u.fu_list);
2260                        inode = file->f_path.dentry->d_inode;
2261                        if (inode_has_perm(cred, inode,
2262                                           FILE__READ | FILE__WRITE, NULL)) {
2263                                drop_tty = 1;
2264                        }
2265                }
2266                file_list_unlock();
2267                tty_kref_put(tty);
2268        }
2269        /* Reset controlling tty. */
2270        if (drop_tty)
2271                no_tty();
2272
2273        /* Revalidate access to inherited open files. */
2274
2275        COMMON_AUDIT_DATA_INIT(&ad, FS);
2276
2277        spin_lock(&files->file_lock);
2278        for (;;) {
2279                unsigned long set, i;
2280                int fd;
2281
2282                j++;
2283                i = j * __NFDBITS;
2284                fdt = files_fdtable(files);
2285                if (i >= fdt->max_fds)
2286                        break;
2287                set = fdt->open_fds->fds_bits[j];
2288                if (!set)
2289                        continue;
2290                spin_unlock(&files->file_lock);
2291                for ( ; set ; i++, set >>= 1) {
2292                        if (set & 1) {
2293                                file = fget(i);
2294                                if (!file)
2295                                        continue;
2296                                if (file_has_perm(cred,
2297                                                  file,
2298                                                  file_to_av(file))) {
2299                                        sys_close(i);
2300                                        fd = get_unused_fd();
2301                                        if (fd != i) {
2302                                                if (fd >= 0)
2303                                                        put_unused_fd(fd);
2304                                                fput(file);
2305                                                continue;
2306                                        }
2307                                        if (devnull) {
2308                                                get_file(devnull);
2309                                        } else {
2310                                                devnull = dentry_open(
2311                                                        dget(selinux_null),
2312                                                        mntget(selinuxfs_mount),
2313                                                        O_RDWR, cred);
2314                                                if (IS_ERR(devnull)) {
2315                                                        devnull = NULL;
2316                                                        put_unused_fd(fd);
2317                                                        fput(file);
2318                                                        continue;
2319                                                }
2320                                        }
2321                                        fd_install(fd, devnull);
2322                                }
2323                                fput(file);
2324                        }
2325                }
2326                spin_lock(&files->file_lock);
2327
2328        }
2329        spin_unlock(&files->file_lock);
2330}
2331
2332/*
2333 * Prepare a process for imminent new credential changes due to exec
2334 */
2335static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2336{
2337        struct task_security_struct *new_tsec;
2338        struct rlimit *rlim, *initrlim;
2339        int rc, i;
2340
2341        new_tsec = bprm->cred->security;
2342        if (new_tsec->sid == new_tsec->osid)
2343                return;
2344
2345        /* Close files for which the new task SID is not authorized. */
2346        flush_unauthorized_files(bprm->cred, current->files);
2347
2348        /* Always clear parent death signal on SID transitions. */
2349        current->pdeath_signal = 0;
2350
2351        /* Check whether the new SID can inherit resource limits from the old
2352         * SID.  If not, reset all soft limits to the lower of the current
2353         * task's hard limit and the init task's soft limit.
2354         *
2355         * Note that the setting of hard limits (even to lower them) can be
2356         * controlled by the setrlimit check.  The inclusion of the init task's
2357         * soft limit into the computation is to avoid resetting soft limits
2358         * higher than the default soft limit for cases where the default is
2359         * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2360         */
2361        rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2362                          PROCESS__RLIMITINH, NULL);
2363        if (rc) {
2364                for (i = 0; i < RLIM_NLIMITS; i++) {
2365                        rlim = current->signal->rlim + i;
2366                        initrlim = init_task.signal->rlim + i;
2367                        rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2368                }
2369                update_rlimit_cpu(rlim->rlim_cur);
2370        }
2371}
2372
2373/*
2374 * Clean up the process immediately after the installation of new credentials
2375 * due to exec
2376 */
2377static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2378{
2379        const struct task_security_struct *tsec = current_security();
2380        struct itimerval itimer;
2381        u32 osid, sid;
2382        int rc, i;
2383
2384        osid = tsec->osid;
2385        sid = tsec->sid;
2386
2387        if (sid == osid)
2388                return;
2389
2390        /* Check whether the new SID can inherit signal state from the old SID.
2391         * If not, clear itimers to avoid subsequent signal generation and
2392         * flush and unblock signals.
2393         *
2394         * This must occur _after_ the task SID has been updated so that any
2395         * kill done after the flush will be checked against the new SID.
2396         */
2397        rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2398        if (rc) {
2399                memset(&itimer, 0, sizeof itimer);
2400                for (i = 0; i < 3; i++)
2401                        do_setitimer(i, &itimer, NULL);
2402                spin_lock_irq(&current->sighand->siglock);
2403                if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2404                        __flush_signals(current);
2405                        flush_signal_handlers(current, 1);
2406                        sigemptyset(&current->blocked);
2407                }
2408                spin_unlock_irq(&current->sighand->siglock);
2409        }
2410
2411        /* Wake up the parent if it is waiting so that it can recheck
2412         * wait permission to the new task SID. */
2413        read_lock(&tasklist_lock);
2414        __wake_up_parent(current, current->real_parent);
2415        read_unlock(&tasklist_lock);
2416}
2417
2418/* superblock security operations */
2419
2420static int selinux_sb_alloc_security(struct super_block *sb)
2421{
2422        return superblock_alloc_security(sb);
2423}
2424
2425static void selinux_sb_free_security(struct super_block *sb)
2426{
2427        superblock_free_security(sb);
2428}
2429
2430static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2431{
2432        if (plen > olen)
2433                return 0;
2434
2435        return !memcmp(prefix, option, plen);
2436}
2437
2438static inline int selinux_option(char *option, int len)
2439{
2440        return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2441                match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2442                match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2443                match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2444                match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2445}
2446
2447static inline void take_option(char **to, char *from, int *first, int len)
2448{
2449        if (!*first) {
2450                **to = ',';
2451                *to += 1;
2452        } else
2453                *first = 0;
2454        memcpy(*to, from, len);
2455        *to += len;
2456}
2457
2458static inline void take_selinux_option(char **to, char *from, int *first,
2459                                       int len)
2460{
2461        int current_size = 0;
2462
2463        if (!*first) {
2464                **to = '|';
2465                *to += 1;
2466        } else
2467                *first = 0;
2468
2469        while (current_size < len) {
2470                if (*from != '"') {
2471                        **to = *from;
2472                        *to += 1;
2473                }
2474                from += 1;
2475                current_size += 1;
2476        }
2477}
2478
2479static int selinux_sb_copy_data(char *orig, char *copy)
2480{
2481        int fnosec, fsec, rc = 0;
2482        char *in_save, *in_curr, *in_end;
2483        char *sec_curr, *nosec_save, *nosec;
2484        int open_quote = 0;
2485
2486        in_curr = orig;
2487        sec_curr = copy;
2488
2489        nosec = (char *)get_zeroed_page(GFP_KERNEL);
2490        if (!nosec) {
2491                rc = -ENOMEM;
2492                goto out;
2493        }
2494
2495        nosec_save = nosec;
2496        fnosec = fsec = 1;
2497        in_save = in_end = orig;
2498
2499        do {
2500                if (*in_end == '"')
2501                        open_quote = !open_quote;
2502                if ((*in_end == ',' && open_quote == 0) ||
2503                                *in_end == '\0') {
2504                        int len = in_end - in_curr;
2505
2506                        if (selinux_option(in_curr, len))
2507                                take_selinux_option(&sec_curr, in_curr, &fsec, len);
2508                        else
2509                                take_option(&nosec, in_curr, &fnosec, len);
2510
2511                        in_curr = in_end + 1;
2512                }
2513        } while (*in_end++);
2514
2515        strcpy(in_save, nosec_save);
2516        free_page((unsigned long)nosec_save);
2517out:
2518        return rc;
2519}
2520
2521static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2522{
2523        const struct cred *cred = current_cred();
2524        struct common_audit_data ad;
2525        int rc;
2526
2527        rc = superblock_doinit(sb, data);
2528        if (rc)
2529                return rc;
2530
2531        /* Allow all mounts performed by the kernel */
2532        if (flags & MS_KERNMOUNT)
2533                return 0;
2534
2535        COMMON_AUDIT_DATA_INIT(&ad, FS);
2536        ad.u.fs.path.dentry = sb->s_root;
2537        return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2538}
2539
2540static int selinux_sb_statfs(struct dentry *dentry)
2541{
2542        const struct cred *cred = current_cred();
2543        struct common_audit_data ad;
2544
2545        COMMON_AUDIT_DATA_INIT(&ad, FS);
2546        ad.u.fs.path.dentry = dentry->d_sb->s_root;
2547        return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2548}
2549
2550static int selinux_mount(char *dev_name,
2551                         struct path *path,
2552                         char *type,
2553                         unsigned long flags,
2554                         void *data)
2555{
2556        const struct cred *cred = current_cred();
2557
2558        if (flags & MS_REMOUNT)
2559                return superblock_has_perm(cred, path->mnt->mnt_sb,
2560                                           FILESYSTEM__REMOUNT, NULL);
2561        else
2562                return dentry_has_perm(cred, path->mnt, path->dentry,
2563                                       FILE__MOUNTON);
2564}
2565
2566static int selinux_umount(struct vfsmount *mnt, int flags)
2567{
2568        const struct cred *cred = current_cred();
2569
2570        return superblock_has_perm(cred, mnt->mnt_sb,
2571                                   FILESYSTEM__UNMOUNT, NULL);
2572}
2573
2574/* inode security operations */
2575
2576static int selinux_inode_alloc_security(struct inode *inode)
2577{
2578        return inode_alloc_security(inode);
2579}
2580
2581static void selinux_inode_free_security(struct inode *inode)
2582{
2583        inode_free_security(inode);
2584}
2585
2586static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2587                                       char **name, void **value,
2588                                       size_t *len)
2589{
2590        const struct cred *cred = current_cred();
2591        const struct task_security_struct *tsec = cred->security;
2592        struct inode_security_struct *dsec;
2593        struct superblock_security_struct *sbsec;
2594        u32 sid, newsid, clen;
2595        int rc;
2596        char *namep = NULL, *context;
2597
2598        dsec = dir->i_security;
2599        sbsec = dir->i_sb->s_security;
2600
2601        sid = tsec->sid;
2602        newsid = tsec->create_sid;
2603
2604        if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2605                rc = security_transition_sid(sid, dsec->sid,
2606                                             inode_mode_to_security_class(inode->i_mode),
2607                                             &newsid);
2608                if (rc) {
2609                        printk(KERN_WARNING "%s:  "
2610                               "security_transition_sid failed, rc=%d (dev=%s "
2611                               "ino=%ld)\n",
2612                               __func__,
2613                               -rc, inode->i_sb->s_id, inode->i_ino);
2614                        return rc;
2615                }
2616        }
2617
2618        /* Possibly defer initialization to selinux_complete_init. */
2619        if (sbsec->flags & SE_SBINITIALIZED) {
2620                struct inode_security_struct *isec = inode->i_security;
2621                isec->sclass = inode_mode_to_security_class(inode->i_mode);
2622                isec->sid = newsid;
2623                isec->initialized = 1;
2624        }
2625
2626        if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2627                return -EOPNOTSUPP;
2628
2629        if (name) {
2630                namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2631                if (!namep)
2632                        return -ENOMEM;
2633                *name = namep;
2634        }
2635
2636        if (value && len) {
2637                rc = security_sid_to_context_force(newsid, &context, &clen);
2638                if (rc) {
2639                        kfree(namep);
2640                        return rc;
2641                }
2642                *value = context;
2643                *len = clen;
2644        }
2645
2646        return 0;
2647}
2648
2649static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2650{
2651        return may_create(dir, dentry, SECCLASS_FILE);
2652}
2653
2654static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2655{
2656        return may_link(dir, old_dentry, MAY_LINK);
2657}
2658
2659static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2660{
2661        return may_link(dir, dentry, MAY_UNLINK);
2662}
2663
2664static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2665{
2666        return may_create(dir, dentry, SECCLASS_LNK_FILE);
2667}
2668
2669static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2670{
2671        return may_create(dir, dentry, SECCLASS_DIR);
2672}
2673
2674static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2675{
2676        return may_link(dir, dentry, MAY_RMDIR);
2677}
2678
2679static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2680{
2681        return may_create(dir, dentry, inode_mode_to_security_class(mode));
2682}
2683
2684static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2685                                struct inode *new_inode, struct dentry *new_dentry)
2686{
2687        return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2688}
2689
2690static int selinux_inode_readlink(struct dentry *dentry)
2691{
2692        const struct cred *cred = current_cred();
2693
2694        return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2695}
2696
2697static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2698{
2699        const struct cred *cred = current_cred();
2700
2701        return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2702}
2703
2704static int selinux_inode_permission(struct inode *inode, int mask)
2705{
2706        const struct cred *cred = current_cred();
2707
2708        if (!mask) {
2709                /* No permission to check.  Existence test. */
2710                return 0;
2711        }
2712
2713        return inode_has_perm(cred, inode,
2714                              file_mask_to_av(inode->i_mode, mask), NULL);
2715}
2716
2717static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2718{
2719        const struct cred *cred = current_cred();
2720        unsigned int ia_valid = iattr->ia_valid;
2721
2722        /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2723        if (ia_valid & ATTR_FORCE) {
2724                ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2725                              ATTR_FORCE);
2726                if (!ia_valid)
2727                        return 0;
2728        }
2729
2730        if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2731                        ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2732                return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2733
2734        return dentry_has_perm(cred, NULL, dentry, FILE__WRITE);
2735}
2736
2737static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2738{
2739        const struct cred *cred = current_cred();
2740
2741        return dentry_has_perm(cred, mnt, dentry, FILE__GETATTR);
2742}
2743
2744static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2745{
2746        const struct cred *cred = current_cred();
2747
2748        if (!strncmp(name, XATTR_SECURITY_PREFIX,
2749                     sizeof XATTR_SECURITY_PREFIX - 1)) {
2750                if (!strcmp(name, XATTR_NAME_CAPS)) {
2751                        if (!capable(CAP_SETFCAP))
2752                                return -EPERM;
2753                } else if (!capable(CAP_SYS_ADMIN)) {
2754                        /* A different attribute in the security namespace.
2755                           Restrict to administrator. */
2756                        return -EPERM;
2757                }
2758        }
2759
2760        /* Not an attribute we recognize, so just check the
2761           ordinary setattr permission. */
2762        return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2763}
2764
2765static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2766                                  const void *value, size_t size, int flags)
2767{
2768        struct inode *inode = dentry->d_inode;
2769        struct inode_security_struct *isec = inode->i_security;
2770        struct superblock_security_struct *sbsec;
2771        struct common_audit_data ad;
2772        u32 newsid, sid = current_sid();
2773        int rc = 0;
2774
2775        if (strcmp(name, XATTR_NAME_SELINUX))
2776                return selinux_inode_setotherxattr(dentry, name);
2777
2778        sbsec = inode->i_sb->s_security;
2779        if (!(sbsec->flags & SE_SBLABELSUPP))
2780                return -EOPNOTSUPP;
2781
2782        if (!is_owner_or_cap(inode))
2783                return -EPERM;
2784
2785        COMMON_AUDIT_DATA_INIT(&ad, FS);
2786        ad.u.fs.path.dentry = dentry;
2787
2788        rc = avc_has_perm(sid, isec->sid, isec->sclass,
2789                          FILE__RELABELFROM, &ad);
2790        if (rc)
2791                return rc;
2792
2793        rc = security_context_to_sid(value, size, &newsid);
2794        if (rc == -EINVAL) {
2795                if (!capable(CAP_MAC_ADMIN))
2796                        return rc;
2797                rc = security_context_to_sid_force(value, size, &newsid);
2798        }
2799        if (rc)
2800                return rc;
2801
2802        rc = avc_has_perm(sid, newsid, isec->sclass,
2803                          FILE__RELABELTO, &ad);
2804        if (rc)
2805                return rc;
2806
2807        rc = security_validate_transition(isec->sid, newsid, sid,
2808                                          isec->sclass);
2809        if (rc)
2810                return rc;
2811
2812        return avc_has_perm(newsid,
2813                            sbsec->sid,
2814                            SECCLASS_FILESYSTEM,
2815                            FILESYSTEM__ASSOCIATE,
2816                            &ad);
2817}
2818
2819static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2820                                        const void *value, size_t size,
2821                                        int flags)
2822{
2823        struct inode *inode = dentry->d_inode;
2824        struct inode_security_struct *isec = inode->i_security;
2825        u32 newsid;
2826        int rc;
2827
2828        if (strcmp(name, XATTR_NAME_SELINUX)) {
2829                /* Not an attribute we recognize, so nothing to do. */
2830                return;
2831        }
2832
2833        rc = security_context_to_sid_force(value, size, &newsid);
2834        if (rc) {
2835                printk(KERN_ERR "SELinux:  unable to map context to SID"
2836                       "for (%s, %lu), rc=%d\n",
2837                       inode->i_sb->s_id, inode->i_ino, -rc);
2838                return;
2839        }
2840
2841        isec->sid = newsid;
2842        return;
2843}
2844
2845static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2846{
2847        const struct cred *cred = current_cred();
2848
2849        return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2850}
2851
2852static int selinux_inode_listxattr(struct dentry *dentry)
2853{
2854        const struct cred *cred = current_cred();
2855
2856        return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2857}
2858
2859static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2860{
2861        if (strcmp(name, XATTR_NAME_SELINUX))
2862                return selinux_inode_setotherxattr(dentry, name);
2863
2864        /* No one is allowed to remove a SELinux security label.
2865           You can change the label, but all data must be labeled. */
2866        return -EACCES;
2867}
2868
2869/*
2870 * Copy the inode security context value to the user.
2871 *
2872 * Permission check is handled by selinux_inode_getxattr hook.
2873 */
2874static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2875{
2876        u32 size;
2877        int error;
2878        char *context = NULL;
2879        struct inode_security_struct *isec = inode->i_security;
2880
2881        if (strcmp(name, XATTR_SELINUX_SUFFIX))
2882                return -EOPNOTSUPP;
2883
2884        /*
2885         * If the caller has CAP_MAC_ADMIN, then get the raw context
2886         * value even if it is not defined by current policy; otherwise,
2887         * use the in-core value under current policy.
2888         * Use the non-auditing forms of the permission checks since
2889         * getxattr may be called by unprivileged processes commonly
2890         * and lack of permission just means that we fall back to the
2891         * in-core context value, not a denial.
2892         */
2893        error = selinux_capable(current, current_cred(), CAP_MAC_ADMIN,
2894                                SECURITY_CAP_NOAUDIT);
2895        if (!error)
2896                error = security_sid_to_context_force(isec->sid, &context,
2897                                                      &size);
2898        else
2899                error = security_sid_to_context(isec->sid, &context, &size);
2900        if (error)
2901                return error;
2902        error = size;
2903        if (alloc) {
2904                *buffer = context;
2905                goto out_nofree;
2906        }
2907        kfree(context);
2908out_nofree:
2909        return error;
2910}
2911
2912static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2913                                     const void *value, size_t size, int flags)
2914{
2915        struct inode_security_struct *isec = inode->i_security;
2916        u32 newsid;
2917        int rc;
2918
2919        if (strcmp(name, XATTR_SELINUX_SUFFIX))
2920                return -EOPNOTSUPP;
2921
2922        if (!value || !size)
2923                return -EACCES;
2924
2925        rc = security_context_to_sid((void *)value, size, &newsid);
2926        if (rc)
2927                return rc;
2928
2929        isec->sid = newsid;
2930        isec->initialized = 1;
2931        return 0;
2932}
2933
2934static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2935{
2936        const int len = sizeof(XATTR_NAME_SELINUX);
2937        if (buffer && len <= buffer_size)
2938                memcpy(buffer, XATTR_NAME_SELINUX, len);
2939        return len;
2940}
2941
2942static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2943{
2944        struct inode_security_struct *isec = inode->i_security;
2945        *secid = isec->sid;
2946}
2947
2948/* file security operations */
2949
2950static int selinux_revalidate_file_permission(struct file *file, int mask)
2951{
2952        const struct cred *cred = current_cred();
2953        struct inode *inode = file->f_path.dentry->d_inode;
2954
2955        /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2956        if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2957                mask |= MAY_APPEND;
2958
2959        return file_has_perm(cred, file,
2960                             file_mask_to_av(inode->i_mode, mask));
2961}
2962
2963static int selinux_file_permission(struct file *file, int mask)
2964{
2965        struct inode *inode = file->f_path.dentry->d_inode;
2966        struct file_security_struct *fsec = file->f_security;
2967        struct inode_security_struct *isec = inode->i_security;
2968        u32 sid = current_sid();
2969
2970        if (!mask)
2971                /* No permission to check.  Existence test. */
2972                return 0;
2973
2974        if (sid == fsec->sid && fsec->isid == isec->sid &&
2975            fsec->pseqno == avc_policy_seqno())
2976                /* No change since dentry_open check. */
2977                return 0;
2978
2979        return selinux_revalidate_file_permission(file, mask);
2980}
2981
2982static int selinux_file_alloc_security(struct file *file)
2983{
2984        return file_alloc_security(file);
2985}
2986
2987static void selinux_file_free_security(struct file *file)
2988{
2989        file_free_security(file);
2990}
2991
2992static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2993                              unsigned long arg)
2994{
2995        const struct cred *cred = current_cred();
2996        u32 av = 0;
2997
2998        if (_IOC_DIR(cmd) & _IOC_WRITE)
2999                av |= FILE__WRITE;
3000        if (_IOC_DIR(cmd) & _IOC_READ)
3001                av |= FILE__READ;
3002        if (!av)
3003                av = FILE__IOCTL;
3004
3005        return file_has_perm(cred, file, av);
3006}
3007
3008static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3009{
3010        const struct cred *cred = current_cred();
3011        int rc = 0;
3012
3013#ifndef CONFIG_PPC32
3014        if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
3015                /*
3016                 * We are making executable an anonymous mapping or a
3017                 * private file mapping that will also be writable.
3018                 * This has an additional check.
3019                 */
3020                rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3021                if (rc)
3022                        goto error;
3023        }
3024#endif
3025
3026        if (file) {
3027                /* read access is always possible with a mapping */
3028                u32 av = FILE__READ;
3029
3030                /* write access only matters if the mapping is shared */
3031                if (shared && (prot & PROT_WRITE))
3032                        av |= FILE__WRITE;
3033
3034                if (prot & PROT_EXEC)
3035                        av |= FILE__EXECUTE;
3036
3037                return file_has_perm(cred, file, av);
3038        }
3039
3040error:
3041        return rc;
3042}
3043
3044static int selinux_file_mmap(struct file *file, unsigned long reqprot,
3045                             unsigned long prot, unsigned long flags,
3046                             unsigned long addr, unsigned long addr_only)
3047{
3048        int rc = 0;
3049        u32 sid = current_sid();
3050
3051        /*
3052         * notice that we are intentionally putting the SELinux check before
3053         * the secondary cap_file_mmap check.  This is such a likely attempt
3054         * at bad behaviour/exploit that we always want to get the AVC, even
3055         * if DAC would have also denied the operation.
3056         */
3057        if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3058                rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3059                                  MEMPROTECT__MMAP_ZERO, NULL);
3060                if (rc)
3061                        return rc;
3062        }
3063
3064        /* do DAC check on address space usage */
3065        rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
3066        if (rc || addr_only)
3067                return rc;
3068
3069        if (selinux_checkreqprot)
3070                prot = reqprot;
3071
3072        return file_map_prot_check(file, prot,
3073                                   (flags & MAP_TYPE) == MAP_SHARED);
3074}
3075
3076static int selinux_file_mprotect(struct vm_area_struct *vma,
3077                                 unsigned long reqprot,
3078                                 unsigned long prot)
3079{
3080        const struct cred *cred = current_cred();
3081
3082        if (selinux_checkreqprot)
3083                prot = reqprot;
3084
3085#ifndef CONFIG_PPC32
3086        if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3087                int rc = 0;
3088                if (vma->vm_start >= vma->vm_mm->start_brk &&
3089                    vma->vm_end <= vma->vm_mm->brk) {
3090                        rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3091                } else if (!vma->vm_file &&
3092                           vma->vm_start <= vma->vm_mm->start_stack &&
3093                           vma->vm_end >= vma->vm_mm->start_stack) {
3094                        rc = current_has_perm(current, PROCESS__EXECSTACK);
3095                } else if (vma->vm_file && vma->anon_vma) {
3096                        /*
3097                         * We are making executable a file mapping that has
3098                         * had some COW done. Since pages might have been
3099                         * written, check ability to execute the possibly
3100                         * modified content.  This typically should only
3101                         * occur for text relocations.
3102                         */
3103                        rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3104                }
3105                if (rc)
3106                        return rc;
3107        }
3108#endif
3109
3110        return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3111}
3112
3113static int selinux_file_lock(struct file *file, unsigned int cmd)
3114{
3115        const struct cred *cred = current_cred();
3116
3117        return file_has_perm(cred, file, FILE__LOCK);
3118}
3119
3120static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3121                              unsigned long arg)
3122{
3123        const struct cred *cred = current_cred();
3124        int err = 0;
3125
3126        switch (cmd) {
3127        case F_SETFL:
3128                if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3129                        err = -EINVAL;
3130                        break;
3131                }
3132
3133                if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3134                        err = file_has_perm(cred, file, FILE__WRITE);
3135                        break;
3136                }
3137                /* fall through */
3138        case F_SETOWN:
3139        case F_SETSIG:
3140        case F_GETFL:
3141        case F_GETOWN:
3142        case F_GETSIG:
3143                /* Just check FD__USE permission */
3144                err = file_has_perm(cred, file, 0);
3145                break;
3146        case F_GETLK:
3147        case F_SETLK:
3148        case F_SETLKW:
3149#if BITS_PER_LONG == 32
3150        case F_GETLK64:
3151        case F_SETLK64:
3152        case F_SETLKW64:
3153#endif
3154                if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3155                        err = -EINVAL;
3156                        break;
3157                }
3158                err = file_has_perm(cred, file, FILE__LOCK);
3159                break;
3160        }
3161
3162        return err;
3163}
3164
3165static int selinux_file_set_fowner(struct file *file)
3166{
3167        struct file_security_struct *fsec;
3168
3169        fsec = file->f_security;
3170        fsec->fown_sid = current_sid();
3171
3172        return 0;
3173}
3174
3175static int selinux_file_send_sigiotask(struct task_struct *tsk,
3176                                       struct fown_struct *fown, int signum)
3177{
3178        struct file *file;
3179        u32 sid = task_sid(tsk);
3180        u32 perm;
3181        struct file_security_struct *fsec;
3182
3183        /* struct fown_struct is never outside the context of a struct file */
3184        file = container_of(fown, struct file, f_owner);
3185
3186        fsec = file->f_security;
3187
3188        if (!signum)
3189                perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3190        else
3191                perm = signal_to_av(signum);
3192
3193        return avc_has_perm(fsec->fown_sid, sid,
3194                            SECCLASS_PROCESS, perm, NULL);
3195}
3196
3197static int selinux_file_receive(struct file *file)
3198{
3199        const struct cred *cred = current_cred();
3200
3201        return file_has_perm(cred, file, file_to_av(file));
3202}
3203
3204static int selinux_dentry_open(struct file *file, const struct cred *cred)
3205{
3206        struct file_security_struct *fsec;
3207        struct inode *inode;
3208        struct inode_security_struct *isec;
3209
3210        inode = file->f_path.dentry->d_inode;
3211        fsec = file->f_security;
3212        isec = inode->i_security;
3213        /*
3214         * Save inode label and policy sequence number
3215         * at open-time so that selinux_file_permission
3216         * can determine whether revalidation is necessary.
3217         * Task label is already saved in the file security
3218         * struct as its SID.
3219         */
3220        fsec->isid = isec->sid;
3221        fsec->pseqno = avc_policy_seqno();
3222        /*
3223         * Since the inode label or policy seqno may have changed
3224         * between the selinux_inode_permission check and the saving
3225         * of state above, recheck that access is still permitted.
3226         * Otherwise, access might never be revalidated against the
3227         * new inode label or new policy.
3228         * This check is not redundant - do not remove.
3229         */
3230        return inode_has_perm(cred, inode, open_file_to_av(file), NULL);
3231}
3232
3233/* task security operations */
3234
3235static int selinux_task_create(unsigned long clone_flags)
3236{
3237        return current_has_perm(current, PROCESS__FORK);
3238}
3239
3240/*
3241 * allocate the SELinux part of blank credentials
3242 */
3243static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3244{
3245        struct task_security_struct *tsec;
3246
3247        tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3248        if (!tsec)
3249                return -ENOMEM;
3250
3251        cred->security = tsec;
3252        return 0;
3253}
3254
3255/*
3256 * detach and free the LSM part of a set of credentials
3257 */
3258static void selinux_cred_free(struct cred *cred)
3259{
3260        struct task_security_struct *tsec = cred->security;
3261
3262        BUG_ON((unsigned long) cred->security < PAGE_SIZE);
3263        cred->security = (void *) 0x7UL;
3264        kfree(tsec);
3265}
3266
3267/*
3268 * prepare a new set of credentials for modification
3269 */
3270static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3271                                gfp_t gfp)
3272{
3273        const struct task_security_struct *old_tsec;
3274        struct task_security_struct *tsec;
3275
3276        old_tsec = old->security;
3277
3278        tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3279        if (!tsec)
3280                return -ENOMEM;
3281
3282        new->security = tsec;
3283        return 0;
3284}
3285
3286/*
3287 * transfer the SELinux data to a blank set of creds
3288 */
3289static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3290{
3291        const struct task_security_struct *old_tsec = old->security;
3292        struct task_security_struct *tsec = new->security;
3293
3294        *tsec = *old_tsec;
3295}
3296
3297/*
3298 * set the security data for a kernel service
3299 * - all the creation contexts are set to unlabelled
3300 */
3301static int selinux_kernel_act_as(struct cred *new, u32 secid)
3302{
3303        struct task_security_struct *tsec = new->security;
3304        u32 sid = current_sid();
3305        int ret;
3306
3307        ret = avc_has_perm(sid, secid,
3308                           SECCLASS_KERNEL_SERVICE,
3309                           KERNEL_SERVICE__USE_AS_OVERRIDE,
3310                           NULL);
3311        if (ret == 0) {
3312                tsec->sid = secid;
3313                tsec->create_sid = 0;
3314                tsec->keycreate_sid = 0;
3315                tsec->sockcreate_sid = 0;
3316        }
3317        return ret;
3318}
3319
3320/*
3321 * set the file creation context in a security record to the same as the
3322 * objective context of the specified inode
3323 */
3324static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3325{
3326        struct inode_security_struct *isec = inode->i_security;
3327        struct task_security_struct *tsec = new->security;
3328        u32 sid = current_sid();
3329        int ret;
3330
3331        ret = avc_has_perm(sid, isec->sid,
3332                           SECCLASS_KERNEL_SERVICE,
3333                           KERNEL_SERVICE__CREATE_FILES_AS,
3334                           NULL);
3335
3336        if (ret == 0)
3337                tsec->create_sid = isec->sid;
3338        return 0;
3339}
3340
3341static int selinux_kernel_module_request(void)
3342{
3343        return task_has_system(current, SYSTEM__MODULE_REQUEST);
3344}
3345
3346static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3347{
3348        return current_has_perm(p, PROCESS__SETPGID);
3349}
3350
3351static int selinux_task_getpgid(struct task_struct *p)
3352{
3353        return current_has_perm(p, PROCESS__GETPGID);
3354}
3355
3356static int selinux_task_getsid(struct task_struct *p)
3357{
3358        return current_has_perm(p, PROCESS__GETSESSION);
3359}
3360
3361static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3362{
3363        *secid = task_sid(p);
3364}
3365
3366static int selinux_task_setnice(struct task_struct *p, int nice)
3367{
3368        int rc;
3369
3370        rc = cap_task_setnice(p, nice);
3371        if (rc)
3372                return rc;
3373
3374        return current_has_perm(p, PROCESS__SETSCHED);
3375}
3376
3377static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3378{
3379        int rc;
3380
3381        rc = cap_task_setioprio(p, ioprio);
3382        if (rc)
3383                return rc;
3384
3385        return current_has_perm(p, PROCESS__SETSCHED);
3386}
3387
3388static int selinux_task_getioprio(struct task_struct *p)
3389{
3390        return current_has_perm(p, PROCESS__GETSCHED);
3391}
3392
3393static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
3394{
3395        struct rlimit *old_rlim = current->signal->rlim + resource;
3396
3397        /* Control the ability to change the hard limit (whether
3398           lowering or raising it), so that the hard limit can
3399           later be used as a safe reset point for the soft limit
3400           upon context transitions.  See selinux_bprm_committing_creds. */
3401        if (old_rlim->rlim_max != new_rlim->rlim_max)
3402                return current_has_perm(current, PROCESS__SETRLIMIT);
3403
3404        return 0;
3405}
3406
3407static int selinux_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp)
3408{
3409        int rc;
3410
3411        rc = cap_task_setscheduler(p, policy, lp);
3412        if (rc)
3413                return rc;
3414
3415        return current_has_perm(p, PROCESS__SETSCHED);
3416}
3417
3418static int selinux_task_getscheduler(struct task_struct *p)
3419{
3420        return current_has_perm(p, PROCESS__GETSCHED);
3421}
3422
3423static int selinux_task_movememory(struct task_struct *p)
3424{
3425        return current_has_perm(p, PROCESS__SETSCHED);
3426}
3427
3428static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3429                                int sig, u32 secid)
3430{
3431        u32 perm;
3432        int rc;
3433
3434        if (!sig)
3435                perm = PROCESS__SIGNULL; /* null signal; existence test */
3436        else
3437                perm = signal_to_av(sig);
3438        if (secid)
3439                rc = avc_has_perm(secid, task_sid(p),
3440                                  SECCLASS_PROCESS, perm, NULL);
3441        else
3442                rc = current_has_perm(p, perm);
3443        return rc;
3444}
3445
3446static int selinux_task_wait(struct task_struct *p)
3447{
3448        return task_has_perm(p, current, PROCESS__SIGCHLD);
3449}
3450
3451static void selinux_task_to_inode(struct task_struct *p,
3452                                  struct inode *inode)
3453{
3454        struct inode_security_struct *isec = inode->i_security;
3455        u32 sid = task_sid(p);
3456
3457        isec->sid = sid;
3458        isec->initialized = 1;
3459}
3460
3461/* Returns error only if unable to parse addresses */
3462static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3463                        struct common_audit_data *ad, u8 *proto)
3464{
3465        int offset, ihlen, ret = -EINVAL;
3466        struct iphdr _iph, *ih;
3467
3468        offset = skb_network_offset(skb);
3469        ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3470        if (ih == NULL)
3471                goto out;
3472
3473        ihlen = ih->ihl * 4;
3474        if (ihlen < sizeof(_iph))
3475                goto out;
3476
3477        ad->u.net.v4info.saddr = ih->saddr;
3478        ad->u.net.v4info.daddr = ih->daddr;
3479        ret = 0;
3480
3481        if (proto)
3482                *proto = ih->protocol;
3483
3484        switch (ih->protocol) {
3485        case IPPROTO_TCP: {
3486                struct tcphdr _tcph, *th;
3487
3488                if (ntohs(ih->frag_off) & IP_OFFSET)
3489                        break;
3490
3491                offset += ihlen;
3492                th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3493                if (th == NULL)
3494                        break;
3495
3496                ad->u.net.sport = th->source;
3497                ad->u.net.dport = th->dest;
3498                break;
3499        }
3500
3501        case IPPROTO_UDP: {
3502                struct udphdr _udph, *uh;
3503
3504                if (ntohs(ih->frag_off) & IP_OFFSET)
3505                        break;
3506
3507                offset += ihlen;
3508                uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3509                if (uh == NULL)
3510                        break;
3511
3512                ad->u.net.sport = uh->source;
3513                ad->u.net.dport = uh->dest;
3514                break;
3515        }
3516
3517        case IPPROTO_DCCP: {
3518                struct dccp_hdr _dccph, *dh;
3519
3520                if (ntohs(ih->frag_off) & IP_OFFSET)
3521                        break;
3522
3523                offset += ihlen;
3524                dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3525                if (dh == NULL)
3526                        break;
3527
3528                ad->u.net.sport = dh->dccph_sport;
3529                ad->u.net.dport = dh->dccph_dport;
3530                break;
3531        }
3532
3533        default:
3534                break;
3535        }
3536out:
3537        return ret;
3538}
3539
3540#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3541
3542/* Returns error only if unable to parse addresses */
3543static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3544                        struct common_audit_data *ad, u8 *proto)
3545{
3546        u8 nexthdr;
3547        int ret = -EINVAL, offset;
3548        struct ipv6hdr _ipv6h, *ip6;
3549
3550        offset = skb_network_offset(skb);
3551        ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3552        if (ip6 == NULL)
3553                goto out;
3554
3555        ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
3556        ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
3557        ret = 0;
3558
3559        nexthdr = ip6->nexthdr;
3560        offset += sizeof(_ipv6h);
3561        offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
3562        if (offset < 0)
3563                goto out;
3564
3565        if (proto)
3566                *proto = nexthdr;
3567
3568        switch (nexthdr) {
3569        case IPPROTO_TCP: {
3570                struct tcphdr _tcph, *th;
3571
3572                th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3573                if (th == NULL)
3574                        break;
3575
3576                ad->u.net.sport = th->source;
3577                ad->u.net.dport = th->dest;
3578                break;
3579        }
3580
3581        case IPPROTO_UDP: {
3582                struct udphdr _udph, *uh;
3583
3584                uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3585                if (uh == NULL)
3586                        break;
3587
3588                ad->u.net.sport = uh->source;
3589                ad->u.net.dport = uh->dest;
3590                break;
3591        }
3592
3593        case IPPROTO_DCCP: {
3594                struct dccp_hdr _dccph, *dh;
3595
3596                dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3597                if (dh == NULL)
3598                        break;
3599
3600                ad->u.net.sport = dh->dccph_sport;
3601                ad->u.net.dport = dh->dccph_dport;
3602                break;
3603        }
3604
3605        /* includes fragments */
3606        default:
3607                break;
3608        }
3609out:
3610        return ret;
3611}
3612
3613#endif /* IPV6 */
3614
3615static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3616                             char **_addrp, int src, u8 *proto)
3617{
3618        char *addrp;
3619        int ret;
3620
3621        switch (ad->u.net.family) {
3622        case PF_INET:
3623                ret = selinux_parse_skb_ipv4(skb, ad, proto);
3624                if (ret)
3625                        goto parse_error;
3626                addrp = (char *)(src ? &ad->u.net.v4info.saddr :
3627                                       &ad->u.net.v4info.daddr);
3628                goto okay;
3629
3630#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3631        case PF_INET6:
3632                ret = selinux_parse_skb_ipv6(skb, ad, proto);
3633                if (ret)
3634                        goto parse_error;
3635                addrp = (char *)(src ? &ad->u.net.v6info.saddr :
3636                                       &ad->u.net.v6info.daddr);
3637                goto okay;
3638#endif  /* IPV6 */
3639        default:
3640                addrp = NULL;
3641                goto okay;
3642        }
3643
3644parse_error:
3645        printk(KERN_WARNING
3646               "SELinux: failure in selinux_parse_skb(),"
3647               " unable to parse packet\n");
3648        return ret;
3649
3650okay:
3651        if (_addrp)
3652                *_addrp = addrp;
3653        return 0;
3654}
3655
3656/**
3657 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3658 * @skb: the packet
3659 * @family: protocol family
3660 * @sid: the packet's peer label SID
3661 *
3662 * Description:
3663 * Check the various different forms of network peer labeling and determine
3664 * the peer label/SID for the packet; most of the magic actually occurs in
3665 * the security server function security_net_peersid_cmp().  The function
3666 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3667 * or -EACCES if @sid is invalid due to inconsistencies with the different
3668 * peer labels.
3669 *
3670 */
3671static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3672{
3673        int err;
3674        u32 xfrm_sid;
3675        u32 nlbl_sid;
3676        u32 nlbl_type;
3677
3678        selinux_skb_xfrm_sid(skb, &xfrm_sid);
3679        selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3680
3681        err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3682        if (unlikely(err)) {
3683                printk(KERN_WARNING
3684                       "SELinux: failure in selinux_skb_peerlbl_sid(),"
3685                       " unable to determine packet's peer label\n");
3686                return -EACCES;
3687        }
3688
3689        return 0;
3690}
3691
3692/* socket security operations */
3693static int socket_has_perm(struct task_struct *task, struct socket *sock,
3694                           u32 perms)
3695{
3696        struct inode_security_struct *isec;
3697        struct common_audit_data ad;
3698        u32 sid;
3699        int err = 0;
3700
3701        isec = SOCK_INODE(sock)->i_security;
3702
3703        if (isec->sid == SECINITSID_KERNEL)
3704                goto out;
3705        sid = task_sid(task);
3706
3707        COMMON_AUDIT_DATA_INIT(&ad, NET);
3708        ad.u.net.sk = sock->sk;
3709        err = avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
3710
3711out:
3712        return err;
3713}
3714
3715static int selinux_socket_create(int family, int type,
3716                                 int protocol, int kern)
3717{
3718        const struct cred *cred = current_cred();
3719        const struct task_security_struct *tsec = cred->security;
3720        u32 sid, newsid;
3721        u16 secclass;
3722        int err = 0;
3723
3724        if (kern)
3725                goto out;
3726
3727        sid = tsec->sid;
3728        newsid = tsec->sockcreate_sid ?: sid;
3729
3730        secclass = socket_type_to_security_class(family, type, protocol);
3731        err = avc_has_perm(sid, newsid, secclass, SOCKET__CREATE, NULL);
3732
3733out:
3734        return err;
3735}
3736
3737static int selinux_socket_post_create(struct socket *sock, int family,
3738                                      int type, int protocol, int kern)
3739{
3740        const struct cred *cred = current_cred();
3741        const struct task_security_struct *tsec = cred->security;
3742        struct inode_security_struct *isec;
3743        struct sk_security_struct *sksec;
3744        u32 sid, newsid;
3745        int err = 0;
3746
3747        sid = tsec->sid;
3748        newsid = tsec->sockcreate_sid;
3749
3750        isec = SOCK_INODE(sock)->i_security;
3751
3752        if (kern)
3753                isec->sid = SECINITSID_KERNEL;
3754        else if (newsid)
3755                isec->sid = newsid;
3756        else
3757                isec->sid = sid;
3758
3759        isec->sclass = socket_type_to_security_class(family, type, protocol);
3760        isec->initialized = 1;
3761
3762        if (sock->sk) {
3763                sksec = sock->sk->sk_security;
3764                sksec->sid = isec->sid;
3765                sksec->sclass = isec->sclass;
3766                err = selinux_netlbl_socket_post_create(sock->sk, family);
3767        }
3768
3769        return err;
3770}
3771
3772/* Range of port numbers used to automatically bind.
3773   Need to determine whether we should perform a name_bind
3774   permission check between the socket and the port number. */
3775
3776static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3777{
3778        u16 family;
3779        int err;
3780
3781        err = socket_has_perm(current, sock, SOCKET__BIND);
3782        if (err)
3783                goto out;
3784
3785        /*
3786         * If PF_INET or PF_INET6, check name_bind permission for the port.
3787         * Multiple address binding for SCTP is not supported yet: we just
3788         * check the first address now.
3789         */
3790        family = sock->sk->sk_family;
3791        if (family == PF_INET || family == PF_INET6) {
3792                char *addrp;
3793                struct inode_security_struct *isec;
3794                struct common_audit_data ad;
3795                struct sockaddr_in *addr4 = NULL;
3796                struct sockaddr_in6 *addr6 = NULL;
3797                unsigned short snum;
3798                struct sock *sk = sock->sk;
3799                u32 sid, node_perm;
3800
3801                isec = SOCK_INODE(sock)->i_security;
3802
3803                if (family == PF_INET) {
3804                        addr4 = (struct sockaddr_in *)address;
3805                        snum = ntohs(addr4->sin_port);
3806                        addrp = (char *)&addr4->sin_addr.s_addr;
3807                } else {
3808                        addr6 = (struct sockaddr_in6 *)address;
3809                        snum = ntohs(addr6->sin6_port);
3810                        addrp = (char *)&addr6->sin6_addr.s6_addr;
3811                }
3812
3813                if (snum) {
3814                        int low, high;
3815
3816                        inet_get_local_port_range(&low, &high);
3817
3818                        if (snum < max(PROT_SOCK, low) || snum > high) {
3819                                err = sel_netport_sid(sk->sk_protocol,
3820                                                      snum, &sid);
3821                                if (err)
3822                                        goto out;
3823                                COMMON_AUDIT_DATA_INIT(&ad, NET);
3824                                ad.u.net.sport = htons(snum);
3825                                ad.u.net.family = family;
3826                                err = avc_has_perm(isec->sid, sid,
3827                                                   isec->sclass,
3828                                                   SOCKET__NAME_BIND, &ad);
3829                                if (err)
3830                                        goto out;
3831                        }
3832                }
3833
3834                switch (isec->sclass) {
3835                case SECCLASS_TCP_SOCKET:
3836                        node_perm = TCP_SOCKET__NODE_BIND;
3837                        break;
3838
3839                case SECCLASS_UDP_SOCKET:
3840                        node_perm = UDP_SOCKET__NODE_BIND;
3841                        break;
3842
3843                case SECCLASS_DCCP_SOCKET:
3844                        node_perm = DCCP_SOCKET__NODE_BIND;
3845                        break;
3846
3847                default:
3848                        node_perm = RAWIP_SOCKET__NODE_BIND;
3849                        break;
3850                }
3851
3852                err = sel_netnode_sid(addrp, family, &sid);
3853                if (err)
3854                        goto out;
3855
3856                COMMON_AUDIT_DATA_INIT(&ad, NET);
3857                ad.u.net.sport = htons(snum);
3858                ad.u.net.family = family;
3859
3860                if (family == PF_INET)
3861                        ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
3862                else
3863                        ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr);
3864
3865                err = avc_has_perm(isec->sid, sid,
3866                                   isec->sclass, node_perm, &ad);
3867                if (err)
3868                        goto out;
3869        }
3870out:
3871        return err;
3872}
3873
3874static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3875{
3876        struct sock *sk = sock->sk;
3877        struct inode_security_struct *isec;
3878        int err;
3879
3880        err = socket_has_perm(current, sock, SOCKET__CONNECT);
3881        if (err)
3882                return err;
3883
3884        /*
3885         * If a TCP or DCCP socket, check name_connect permission for the port.
3886         */
3887        isec = SOCK_INODE(sock)->i_security;
3888        if (isec->sclass == SECCLASS_TCP_SOCKET ||
3889            isec->sclass == SECCLASS_DCCP_SOCKET) {
3890                struct common_audit_data ad;
3891                struct sockaddr_in *addr4 = NULL;
3892                struct sockaddr_in6 *addr6 = NULL;
3893                unsigned short snum;
3894                u32 sid, perm;
3895
3896                if (sk->sk_family == PF_INET) {
3897                        addr4 = (struct sockaddr_in *)address;
3898                        if (addrlen < sizeof(struct sockaddr_in))
3899                                return -EINVAL;
3900                        snum = ntohs(addr4->sin_port);
3901                } else {
3902                        addr6 = (struct sockaddr_in6 *)address;
3903                        if (addrlen < SIN6_LEN_RFC2133)
3904                                return -EINVAL;
3905                        snum = ntohs(addr6->sin6_port);
3906                }
3907
3908                err = sel_netport_sid(sk->sk_protocol, snum, &sid);
3909                if (err)
3910                        goto out;
3911
3912                perm = (isec->sclass == SECCLASS_TCP_SOCKET) ?
3913                       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
3914
3915                COMMON_AUDIT_DATA_INIT(&ad, NET);
3916                ad.u.net.dport = htons(snum);
3917                ad.u.net.family = sk->sk_family;
3918                err = avc_has_perm(isec->sid, sid, isec->sclass, perm, &ad);
3919                if (err)
3920                        goto out;
3921        }
3922
3923        err = selinux_netlbl_socket_connect(sk, address);
3924
3925out:
3926        return err;
3927}
3928
3929static int selinux_socket_listen(struct socket *sock, int backlog)
3930{
3931        return socket_has_perm(current, sock, SOCKET__LISTEN);
3932}
3933
3934static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3935{
3936        int err;
3937        struct inode_security_struct *isec;
3938        struct inode_security_struct *newisec;
3939
3940        err = socket_has_perm(current, sock, SOCKET__ACCEPT);
3941        if (err)
3942                return err;
3943
3944        newisec = SOCK_INODE(newsock)->i_security;
3945
3946        isec = SOCK_INODE(sock)->i_security;
3947        newisec->sclass = isec->sclass;
3948        newisec->sid = isec->sid;
3949        newisec->initialized = 1;
3950
3951        return 0;
3952}
3953
3954static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3955                                  int size)
3956{
3957        return socket_has_perm(current, sock, SOCKET__WRITE);
3958}
3959
3960static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
3961                                  int size, int flags)
3962{
3963        return socket_has_perm(current, sock, SOCKET__READ);
3964}
3965
3966static int selinux_socket_getsockname(struct socket *sock)
3967{
3968        return socket_has_perm(current, sock, SOCKET__GETATTR);
3969}
3970
3971static int selinux_socket_getpeername(struct socket *sock)
3972{
3973        return socket_has_perm(current, sock, SOCKET__GETATTR);
3974}
3975
3976static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
3977{
3978        int err;
3979
3980        err = socket_has_perm(current, sock, SOCKET__SETOPT);
3981        if (err)
3982                return err;
3983
3984        return selinux_netlbl_socket_setsockopt(sock, level, optname);
3985}
3986
3987static int selinux_socket_getsockopt(struct socket *sock, int level,
3988                                     int optname)
3989{
3990        return socket_has_perm(current, sock, SOCKET__GETOPT);
3991}
3992
3993static int selinux_socket_shutdown(struct socket *sock, int how)
3994{
3995        return socket_has_perm(current, sock, SOCKET__SHUTDOWN);
3996}
3997
3998static int selinux_socket_unix_stream_connect(struct socket *sock,
3999                                              struct socket *other,
4000                                              struct sock *newsk)
4001{
4002        struct sk_security_struct *ssec;
4003        struct inode_security_struct *isec;
4004        struct inode_security_struct *other_isec;
4005        struct common_audit_data ad;
4006        int err;
4007
4008        isec = SOCK_INODE(sock)->i_security;
4009        other_isec = SOCK_INODE(other)->i_security;
4010
4011        COMMON_AUDIT_DATA_INIT(&ad, NET);
4012        ad.u.net.sk = other->sk;
4013
4014        err = avc_has_perm(isec->sid, other_isec->sid,
4015                           isec->sclass,
4016                           UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4017        if (err)
4018                return err;
4019
4020        /* connecting socket */
4021        ssec = sock->sk->sk_security;
4022        ssec->peer_sid = other_isec->sid;
4023
4024        /* server child socket */
4025        ssec = newsk->sk_security;
4026        ssec->peer_sid = isec->sid;
4027        err = security_sid_mls_copy(other_isec->sid, ssec->peer_sid, &ssec->sid);
4028
4029        return err;
4030}
4031
4032static int selinux_socket_unix_may_send(struct socket *sock,
4033                                        struct socket *other)
4034{
4035        struct inode_security_struct *isec;
4036        struct inode_security_struct *other_isec;
4037        struct common_audit_data ad;
4038        int err;
4039
4040        isec = SOCK_INODE(sock)->i_security;
4041        other_isec = SOCK_INODE(other)->i_security;
4042
4043        COMMON_AUDIT_DATA_INIT(&ad, NET);
4044        ad.u.net.sk = other->sk;
4045
4046        err = avc_has_perm(isec->sid, other_isec->sid,
4047                           isec->sclass, SOCKET__SENDTO, &ad);
4048        if (err)
4049                return err;
4050
4051        return 0;
4052}
4053
4054static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
4055                                    u32 peer_sid,
4056                                    struct common_audit_data *ad)
4057{
4058        int err;
4059        u32 if_sid;
4060        u32 node_sid;
4061
4062        err = sel_netif_sid(ifindex, &if_sid);
4063        if (err)
4064                return err;
4065        err = avc_has_perm(peer_sid, if_sid,
4066                           SECCLASS_NETIF, NETIF__INGRESS, ad);
4067        if (err)
4068                return err;
4069
4070        err = sel_netnode_sid(addrp, family, &node_sid);
4071        if (err)
4072                return err;
4073        return avc_has_perm(peer_sid, node_sid,
4074                            SECCLASS_NODE, NODE__RECVFROM, ad);
4075}
4076
4077static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4078                                       u16 family)
4079{
4080        int err = 0;
4081        struct sk_security_struct *sksec = sk->sk_security;
4082        u32 peer_sid;
4083        u32 sk_sid = sksec->sid;
4084        struct common_audit_data ad;
4085        char *addrp;
4086
4087        COMMON_AUDIT_DATA_INIT(&ad, NET);
4088        ad.u.net.netif = skb->iif;
4089        ad.u.net.family = family;
4090        err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4091        if (err)
4092                return err;
4093
4094        if (selinux_secmark_enabled()) {
4095                err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4096                                   PACKET__RECV, &ad);
4097                if (err)
4098                        return err;
4099        }
4100
4101        if (selinux_policycap_netpeer) {
4102                err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4103                if (err)
4104                        return err;
4105                err = avc_has_perm(sk_sid, peer_sid,
4106                                   SECCLASS_PEER, PEER__RECV, &ad);
4107                if (err)
4108                        selinux_netlbl_err(skb, err, 0);
4109        } else {
4110                err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4111                if (err)
4112                        return err;
4113                err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4114        }
4115
4116        return err;
4117}
4118
4119static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4120{
4121        int err;
4122        struct sk_security_struct *sksec = sk->sk_security;
4123        u16 family = sk->sk_family;
4124        u32 sk_sid = sksec->sid;
4125        struct common_audit_data ad;
4126        char *addrp;
4127        u8 secmark_active;
4128        u8 peerlbl_active;
4129
4130        if (family != PF_INET && family != PF_INET6)
4131                return 0;
4132
4133        /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4134        if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4135                family = PF_INET;
4136
4137        /* If any sort of compatibility mode is enabled then handoff processing
4138         * to the selinux_sock_rcv_skb_compat() function to deal with the
4139         * special handling.  We do this in an attempt to keep this function
4140         * as fast and as clean as possible. */
4141        if (!selinux_policycap_netpeer)
4142                return selinux_sock_rcv_skb_compat(sk, skb, family);
4143
4144        secmark_active = selinux_secmark_enabled();
4145        peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4146        if (!secmark_active && !peerlbl_active)
4147                return 0;
4148
4149        COMMON_AUDIT_DATA_INIT(&ad, NET);
4150        ad.u.net.netif = skb->iif;
4151        ad.u.net.family = family;
4152        err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4153        if (err)
4154                return err;
4155
4156        if (peerlbl_active) {
4157                u32 peer_sid;
4158
4159                err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4160                if (err)
4161                        return err;
4162                err = selinux_inet_sys_rcv_skb(skb->iif, addrp, family,
4163                                               peer_sid, &ad);
4164                if (err) {
4165                        selinux_netlbl_err(skb, err, 0);
4166                        return err;
4167                }
4168                err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4169                                   PEER__RECV, &ad);
4170                if (err)
4171                        selinux_netlbl_err(skb, err, 0);
4172        }
4173
4174        if (secmark_active) {
4175                err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4176                                   PACKET__RECV, &ad);
4177                if (err)
4178                        return err;
4179        }
4180
4181        return err;
4182}
4183
4184static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4185                                            int __user *optlen, unsigned len)
4186{
4187        int err = 0;
4188        char *scontext;
4189        u32 scontext_len;
4190        struct sk_security_struct *ssec;
4191        struct inode_security_struct *isec;
4192        u32 peer_sid = SECSID_NULL;
4193
4194        isec = SOCK_INODE(sock)->i_security;
4195
4196        if (isec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4197            isec->sclass == SECCLASS_TCP_SOCKET) {
4198                ssec = sock->sk->sk_security;
4199                peer_sid = ssec->peer_sid;
4200        }
4201        if (peer_sid == SECSID_NULL) {
4202                err = -ENOPROTOOPT;
4203                goto out;
4204        }
4205
4206        err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4207
4208        if (err)
4209                goto out;
4210
4211        if (scontext_len > len) {
4212                err = -ERANGE;
4213                goto out_len;
4214        }
4215
4216        if (copy_to_user(optval, scontext, scontext_len))
4217                err = -EFAULT;
4218
4219out_len:
4220        if (put_user(scontext_len, optlen))
4221                err = -EFAULT;
4222
4223        kfree(scontext);
4224out:
4225        return err;
4226}
4227
4228static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4229{
4230        u32 peer_secid = SECSID_NULL;
4231        u16 family;
4232
4233        if (skb && skb->protocol == htons(ETH_P_IP))
4234                family = PF_INET;
4235        else if (skb && skb->protocol == htons(ETH_P_IPV6))
4236                family = PF_INET6;
4237        else if (sock)
4238                family = sock->sk->sk_family;
4239        else
4240                goto out;
4241
4242        if (sock && family == PF_UNIX)
4243                selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4244        else if (skb)
4245                selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4246
4247out:
4248        *secid = peer_secid;
4249        if (peer_secid == SECSID_NULL)
4250                return -EINVAL;
4251        return 0;
4252}
4253
4254static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4255{
4256        return sk_alloc_security(sk, family, priority);
4257}
4258
4259static void selinux_sk_free_security(struct sock *sk)
4260{
4261        sk_free_security(sk);
4262}
4263
4264static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4265{
4266        struct sk_security_struct *ssec = sk->sk_security;
4267        struct sk_security_struct *newssec = newsk->sk_security;
4268
4269        newssec->sid = ssec->sid;
4270        newssec->peer_sid = ssec->peer_sid;
4271        newssec->sclass = ssec->sclass;
4272
4273        selinux_netlbl_sk_security_reset(newssec);
4274}
4275
4276static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4277{
4278        if (!sk)
4279                *secid = SECINITSID_ANY_SOCKET;
4280        else {
4281                struct sk_security_struct *sksec = sk->sk_security;
4282
4283                *secid = sksec->sid;
4284        }
4285}
4286
4287static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4288{
4289        struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4290        struct sk_security_struct *sksec = sk->sk_security;
4291
4292        if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4293            sk->sk_family == PF_UNIX)
4294                isec->sid = sksec->sid;
4295        sksec->sclass = isec->sclass;
4296}
4297
4298static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4299                                     struct request_sock *req)
4300{
4301        struct sk_security_struct *sksec = sk->sk_security;
4302        int err;
4303        u16 family = sk->sk_family;
4304        u32 newsid;
4305        u32 peersid;
4306
4307        /* handle mapped IPv4 packets arriving via IPv6 sockets */
4308        if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4309                family = PF_INET;
4310
4311        err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4312        if (err)
4313                return err;
4314        if (peersid == SECSID_NULL) {
4315                req->secid = sksec->sid;
4316                req->peer_secid = SECSID_NULL;
4317        } else {
4318                err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
4319                if (err)
4320                        return err;
4321                req->secid = newsid;
4322                req->peer_secid = peersid;
4323        }
4324
4325        return selinux_netlbl_inet_conn_request(req, family);
4326}
4327
4328static void selinux_inet_csk_clone(struct sock *newsk,
4329                                   const struct request_sock *req)
4330{
4331        struct sk_security_struct *newsksec = newsk->sk_security;
4332
4333        newsksec->sid = req->secid;
4334        newsksec->peer_sid = req->peer_secid;
4335        /* NOTE: Ideally, we should also get the isec->sid for the
4336           new socket in sync, but we don't have the isec available yet.
4337           So we will wait until sock_graft to do it, by which
4338           time it will have been created and available. */
4339
4340        /* We don't need to take any sort of lock here as we are the only
4341         * thread with access to newsksec */
4342        selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4343}
4344
4345static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4346{
4347        u16 family = sk->sk_family;
4348        struct sk_security_struct *sksec = sk->sk_security;
4349
4350        /* handle mapped IPv4 packets arriving via IPv6 sockets */
4351        if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4352                family = PF_INET;
4353
4354        selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4355}
4356
4357static void selinux_req_classify_flow(const struct request_sock *req,
4358                                      struct flowi *fl)
4359{
4360        fl->secid = req->secid;
4361}
4362
4363static int selinux_tun_dev_create(void)
4364{
4365        u32 sid = current_sid();
4366
4367        /* we aren't taking into account the "sockcreate" SID since the socket
4368         * that is being created here is not a socket in the traditional sense,
4369         * instead it is a private sock, accessible only to the kernel, and
4370         * representing a wide range of network traffic spanning multiple
4371         * connections unlike traditional sockets - check the TUN driver to
4372         * get a better understanding of why this socket is special */
4373
4374        return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4375                            NULL);
4376}
4377
4378static void selinux_tun_dev_post_create(struct sock *sk)
4379{
4380        struct sk_security_struct *sksec = sk->sk_security;
4381
4382        /* we don't currently perform any NetLabel based labeling here and it
4383         * isn't clear that we would want to do so anyway; while we could apply
4384         * labeling without the support of the TUN user the resulting labeled
4385         * traffic from the other end of the connection would almost certainly
4386         * cause confusion to the TUN user that had no idea network labeling
4387         * protocols were being used */
4388
4389        /* see the comments in selinux_tun_dev_create() about why we don't use
4390         * the sockcreate SID here */
4391
4392        sksec->sid = current_sid();
4393        sksec->sclass = SECCLASS_TUN_SOCKET;
4394}
4395
4396static int selinux_tun_dev_attach(struct sock *sk)
4397{
4398        struct sk_security_struct *sksec = sk->sk_security;
4399        u32 sid = current_sid();
4400        int err;
4401
4402        err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4403                           TUN_SOCKET__RELABELFROM, NULL);
4404        if (err)
4405                return err;
4406        err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4407                           TUN_SOCKET__RELABELTO, NULL);
4408        if (err)
4409                return err;
4410
4411        sksec->sid = sid;
4412
4413        return 0;
4414}
4415
4416static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4417{
4418        int err = 0;
4419        u32 perm;
4420        struct nlmsghdr *nlh;
4421        struct socket *sock = sk->sk_socket;
4422        struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
4423
4424        if (skb->len < NLMSG_SPACE(0)) {
4425                err = -EINVAL;
4426                goto out;
4427        }
4428        nlh = nlmsg_hdr(skb);
4429
4430        err = selinux_nlmsg_lookup(isec->sclass, nlh->nlmsg_type, &perm);
4431        if (err) {
4432                if (err == -EINVAL) {
4433                        audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4434                                  "SELinux:  unrecognized netlink message"
4435                                  " type=%hu for sclass=%hu\n",
4436                                  nlh->nlmsg_type, isec->sclass);
4437                        if (!selinux_enforcing || security_get_allow_unknown())
4438                                err = 0;
4439                }
4440
4441                /* Ignore */
4442                if (err == -ENOENT)
4443                        err = 0;
4444                goto out;
4445        }
4446
4447        err = socket_has_perm(current, sock, perm);
4448out:
4449        return err;
4450}
4451
4452#ifdef CONFIG_NETFILTER
4453
4454static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4455                                       u16 family)
4456{
4457        int err;
4458        char *addrp;
4459        u32 peer_sid;
4460        struct common_audit_data ad;
4461        u8 secmark_active;
4462        u8 netlbl_active;
4463        u8 peerlbl_active;
4464
4465        if (!selinux_policycap_netpeer)
4466                return NF_ACCEPT;
4467
4468        secmark_active = selinux_secmark_enabled();
4469        netlbl_active = netlbl_enabled();
4470        peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4471        if (!secmark_active && !peerlbl_active)
4472                return NF_ACCEPT;
4473
4474        if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4475                return NF_DROP;
4476
4477        COMMON_AUDIT_DATA_INIT(&ad, NET);
4478        ad.u.net.netif = ifindex;
4479        ad.u.net.family = family;
4480        if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4481                return NF_DROP;
4482
4483        if (peerlbl_active) {
4484                err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4485                                               peer_sid, &ad);
4486                if (err) {
4487                        selinux_netlbl_err(skb, err, 1);
4488                        return NF_DROP;
4489                }
4490        }
4491
4492        if (secmark_active)
4493                if (avc_has_perm(peer_sid, skb->secmark,
4494                                 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4495                        return NF_DROP;
4496
4497        if (netlbl_active)
4498                /* we do this in the FORWARD path and not the POST_ROUTING
4499                 * path because we want to make sure we apply the necessary
4500                 * labeling before IPsec is applied so we can leverage AH
4501                 * protection */
4502                if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4503                        return NF_DROP;
4504
4505        return NF_ACCEPT;
4506}
4507
4508static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4509                                         struct sk_buff *skb,
4510                                         const struct net_device *in,
4511                                         const struct net_device *out,
4512                                         int (*okfn)(struct sk_buff *))
4513{
4514        return selinux_ip_forward(skb, in->ifindex, PF_INET);
4515}
4516
4517#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4518static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4519                                         struct sk_buff *skb,
4520                                         const struct net_device *in,
4521                                         const struct net_device *out,
4522                                         int (*okfn)(struct sk_buff *))
4523{
4524        return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4525}
4526#endif  /* IPV6 */
4527
4528static unsigned int selinux_ip_output(struct sk_buff *skb,
4529                                      u16 family)
4530{
4531        u32 sid;
4532
4533        if (!netlbl_enabled())
4534                return NF_ACCEPT;
4535
4536        /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4537         * because we want to make sure we apply the necessary labeling
4538         * before IPsec is applied so we can leverage AH protection */
4539        if (skb->sk) {
4540                struct sk_security_struct *sksec = skb->sk->sk_security;
4541                sid = sksec->sid;
4542        } else
4543                sid = SECINITSID_KERNEL;
4544        if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4545                return NF_DROP;
4546
4547        return NF_ACCEPT;
4548}
4549
4550static unsigned int selinux_ipv4_output(unsigned int hooknum,
4551                                        struct sk_buff *skb,
4552                                        const struct net_device *in,
4553                                        const struct net_device *out,
4554                                        int (*okfn)(struct sk_buff *))
4555{
4556        return selinux_ip_output(skb, PF_INET);
4557}
4558
4559static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4560                                                int ifindex,
4561                                                u16 family)
4562{
4563        struct sock *sk = skb->sk;
4564        struct sk_security_struct *sksec;
4565        struct common_audit_data ad;
4566        char *addrp;
4567        u8 proto;
4568
4569        if (sk == NULL)
4570                return NF_ACCEPT;
4571        sksec = sk->sk_security;
4572
4573        COMMON_AUDIT_DATA_INIT(&ad, NET);
4574        ad.u.net.netif = ifindex;
4575        ad.u.net.family = family;
4576        if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4577                return NF_DROP;
4578
4579        if (selinux_secmark_enabled())
4580                if (avc_has_perm(sksec->sid, skb->secmark,
4581                                 SECCLASS_PACKET, PACKET__SEND, &ad))
4582                        return NF_DROP;
4583
4584        if (selinux_policycap_netpeer)
4585                if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4586                        return NF_DROP;
4587
4588        return NF_ACCEPT;
4589}
4590
4591static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4592                                         u16 family)
4593{
4594        u32 secmark_perm;
4595        u32 peer_sid;
4596        struct sock *sk;
4597        struct common_audit_data ad;
4598        char *addrp;
4599        u8 secmark_active;
4600        u8 peerlbl_active;
4601
4602        /* If any sort of compatibility mode is enabled then handoff processing
4603         * to the selinux_ip_postroute_compat() function to deal with the
4604         * special handling.  We do this in an attempt to keep this function
4605         * as fast and as clean as possible. */
4606        if (!selinux_policycap_netpeer)
4607                return selinux_ip_postroute_compat(skb, ifindex, family);
4608#ifdef CONFIG_XFRM
4609        /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4610         * packet transformation so allow the packet to pass without any checks
4611         * since we'll have another chance to perform access control checks
4612         * when the packet is on it's final way out.
4613         * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4614         *       is NULL, in this case go ahead and apply access control. */
4615        if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4616                return NF_ACCEPT;
4617#endif
4618        secmark_active = selinux_secmark_enabled();
4619        peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4620        if (!secmark_active && !peerlbl_active)
4621                return NF_ACCEPT;
4622
4623        /* if the packet is being forwarded then get the peer label from the
4624         * packet itself; otherwise check to see if it is from a local
4625         * application or the kernel, if from an application get the peer label
4626         * from the sending socket, otherwise use the kernel's sid */
4627        sk = skb->sk;
4628        if (sk == NULL) {
4629                switch (family) {
4630                case PF_INET:
4631                        if (IPCB(skb)->flags & IPSKB_FORWARDED)
4632                                secmark_perm = PACKET__FORWARD_OUT;
4633                        else
4634                                secmark_perm = PACKET__SEND;
4635                        break;
4636                case PF_INET6:
4637                        if (IP6CB(skb)->flags & IP6SKB_FORWARDED)
4638                                secmark_perm = PACKET__FORWARD_OUT;
4639                        else
4640                                secmark_perm = PACKET__SEND;
4641                        break;
4642                default:
4643                        return NF_DROP;
4644                }
4645                if (secmark_perm == PACKET__FORWARD_OUT) {
4646                        if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4647                                return NF_DROP;
4648                } else
4649                        peer_sid = SECINITSID_KERNEL;
4650        } else {
4651                struct sk_security_struct *sksec = sk->sk_security;
4652                peer_sid = sksec->sid;
4653                secmark_perm = PACKET__SEND;
4654        }
4655
4656        COMMON_AUDIT_DATA_INIT(&ad, NET);
4657        ad.u.net.netif = ifindex;
4658        ad.u.net.family = family;
4659        if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4660                return NF_DROP;
4661
4662        if (secmark_active)
4663                if (avc_has_perm(peer_sid, skb->secmark,
4664                                 SECCLASS_PACKET, secmark_perm, &ad))
4665                        return NF_DROP;
4666
4667        if (peerlbl_active) {
4668                u32 if_sid;
4669                u32 node_sid;
4670
4671                if (sel_netif_sid(ifindex, &if_sid))
4672                        return NF_DROP;
4673                if (avc_has_perm(peer_sid, if_sid,
4674                                 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4675                        return NF_DROP;
4676
4677                if (sel_netnode_sid(addrp, family, &node_sid))
4678                        return NF_DROP;
4679                if (avc_has_perm(peer_sid, node_sid,
4680                                 SECCLASS_NODE, NODE__SENDTO, &ad))
4681                        return NF_DROP;
4682        }
4683
4684        return NF_ACCEPT;
4685}
4686
4687static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4688                                           struct sk_buff *skb,
4689                                           const struct net_device *in,
4690                                           const struct net_device *out,
4691                                           int (*okfn)(struct sk_buff *))
4692{
4693        return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4694}
4695
4696#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4697static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4698                                           struct sk_buff *skb,
4699                                           const struct net_device *in,
4700                                           const struct net_device *out,
4701                                           int (*okfn)(struct sk_buff *))
4702{
4703        return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4704}
4705#endif  /* IPV6 */
4706
4707#endif  /* CONFIG_NETFILTER */
4708
4709static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4710{
4711        int err;
4712
4713        err = cap_netlink_send(sk, skb);
4714        if (err)
4715                return err;
4716
4717        if (policydb_loaded_version >= POLICYDB_VERSION_NLCLASS)
4718                err = selinux_nlmsg_perm(sk, skb);
4719
4720        return err;
4721}
4722
4723static int selinux_netlink_recv(struct sk_buff *skb, int capability)
4724{
4725        int err;
4726        struct common_audit_data ad;
4727
4728        err = cap_netlink_recv(skb, capability);
4729        if (err)
4730                return err;
4731
4732        COMMON_AUDIT_DATA_INIT(&ad, CAP);
4733        ad.u.cap = capability;
4734
4735        return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid,
4736                            SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad);
4737}
4738
4739static int ipc_alloc_security(struct task_struct *task,
4740                              struct kern_ipc_perm *perm,
4741                              u16 sclass)
4742{
4743        struct ipc_security_struct *isec;
4744        u32 sid;
4745
4746        isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4747        if (!isec)
4748                return -ENOMEM;
4749
4750        sid = task_sid(task);
4751        isec->sclass = sclass;
4752        isec->sid = sid;
4753        perm->security = isec;
4754
4755        return 0;
4756}
4757
4758static void ipc_free_security(struct kern_ipc_perm *perm)
4759{
4760        struct ipc_security_struct *isec = perm->security;
4761        perm->security = NULL;
4762        kfree(isec);
4763}
4764
4765static int msg_msg_alloc_security(struct msg_msg *msg)
4766{
4767        struct msg_security_struct *msec;
4768
4769        msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4770        if (!msec)
4771                return -ENOMEM;
4772
4773        msec->sid = SECINITSID_UNLABELED;
4774        msg->security = msec;
4775
4776        return 0;
4777}
4778
4779static void msg_msg_free_security(struct msg_msg *msg)
4780{
4781        struct msg_security_struct *msec = msg->security;
4782
4783        msg->security = NULL;
4784        kfree(msec);
4785}
4786
4787static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4788                        u32 perms)
4789{
4790        struct ipc_security_struct *isec;
4791        struct common_audit_data ad;
4792        u32 sid = current_sid();
4793
4794        isec = ipc_perms->security;
4795
4796        COMMON_AUDIT_DATA_INIT(&ad, IPC);
4797        ad.u.ipc_id = ipc_perms->key;
4798
4799        return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4800}
4801
4802static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4803{
4804        return msg_msg_alloc_security(msg);
4805}
4806
4807static void selinux_msg_msg_free_security(struct msg_msg *msg)
4808{
4809        msg_msg_free_security(msg);
4810}
4811
4812/* message queue security operations */
4813static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4814{
4815        struct ipc_security_struct *isec;
4816        struct common_audit_data ad;
4817        u32 sid = current_sid();
4818        int rc;
4819
4820        rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4821        if (rc)
4822                return rc;
4823
4824        isec = msq->q_perm.security;
4825
4826        COMMON_AUDIT_DATA_INIT(&ad, IPC);
4827        ad.u.ipc_id = msq->q_perm.key;
4828
4829        rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4830                          MSGQ__CREATE, &ad);
4831        if (rc) {
4832                ipc_free_security(&msq->q_perm);
4833                return rc;
4834        }
4835        return 0;
4836}
4837
4838static void selinux_msg_queue_free_security(struct msg_queue *msq)
4839{
4840        ipc_free_security(&msq->q_perm);
4841}
4842
4843static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4844{
4845        struct ipc_security_struct *isec;
4846        struct common_audit_data ad;
4847        u32 sid = current_sid();
4848
4849        isec = msq->q_perm.security;
4850
4851        COMMON_AUDIT_DATA_INIT(&ad, IPC);
4852        ad.u.ipc_id = msq->q_perm.key;
4853
4854        return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4855                            MSGQ__ASSOCIATE, &ad);
4856}
4857
4858static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4859{
4860        int err;
4861        int perms;
4862
4863        switch (cmd) {
4864        case IPC_INFO:
4865        case MSG_INFO:
4866                /* No specific object, just general system-wide information. */
4867                return task_has_system(current, SYSTEM__IPC_INFO);
4868        case IPC_STAT:
4869        case MSG_STAT:
4870                perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4871                break;
4872        case IPC_SET:
4873                perms = MSGQ__SETATTR;
4874                break;
4875        case IPC_RMID:
4876                perms = MSGQ__DESTROY;
4877                break;
4878        default:
4879                return 0;
4880        }
4881
4882        err = ipc_has_perm(&msq->q_perm, perms);
4883        return err;
4884}
4885
4886static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4887{
4888        struct ipc_security_struct *isec;
4889        struct msg_security_struct *msec;
4890        struct common_audit_data ad;
4891        u32 sid = current_sid();
4892        int rc;
4893
4894        isec = msq->q_perm.security;
4895        msec = msg->security;
4896
4897        /*
4898         * First time through, need to assign label to the message
4899         */
4900        if (msec->sid == SECINITSID_UNLABELED) {
4901                /*
4902                 * Compute new sid based on current process and
4903                 * message queue this message will be stored in
4904                 */
4905                rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
4906                                             &msec->sid);
4907                if (rc)
4908                        return rc;
4909        }
4910
4911        COMMON_AUDIT_DATA_INIT(&ad, IPC);
4912        ad.u.ipc_id = msq->q_perm.key;
4913
4914        /* Can this process write to the queue? */
4915        rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4916                          MSGQ__WRITE, &ad);
4917        if (!rc)
4918                /* Can this process send the message */
4919                rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
4920                                  MSG__SEND, &ad);
4921        if (!rc)
4922                /* Can the message be put in the queue? */
4923                rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
4924                                  MSGQ__ENQUEUE, &ad);
4925
4926        return rc;
4927}
4928
4929static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
4930                                    struct task_struct *target,
4931                                    long type, int mode)
4932{
4933        struct ipc_security_struct *isec;
4934        struct msg_security_struct *msec;
4935        struct common_audit_data ad;
4936        u32 sid = task_sid(target);
4937        int rc;
4938
4939        isec = msq->q_perm.security;
4940        msec = msg->security;
4941
4942        COMMON_AUDIT_DATA_INIT(&ad, IPC);
4943        ad.u.ipc_id = msq->q_perm.key;
4944
4945        rc = avc_has_perm(sid, isec->sid,
4946                          SECCLASS_MSGQ, MSGQ__READ, &ad);
4947        if (!rc)
4948                rc = avc_has_perm(sid, msec->sid,
4949                                  SECCLASS_MSG, MSG__RECEIVE, &ad);
4950        return rc;
4951}
4952
4953/* Shared Memory security operations */
4954static int selinux_shm_alloc_security(struct shmid_kernel *shp)
4955{
4956        struct ipc_security_struct *isec;
4957        struct common_audit_data ad;
4958        u32 sid = current_sid();
4959        int rc;
4960
4961        rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
4962        if (rc)
4963                return rc;
4964
4965        isec = shp->shm_perm.security;
4966
4967        COMMON_AUDIT_DATA_INIT(&ad, IPC);
4968        ad.u.ipc_id = shp->shm_perm.key;
4969
4970        rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4971                          SHM__CREATE, &ad);
4972        if (rc) {
4973                ipc_free_security(&shp->shm_perm);
4974                return rc;
4975        }
4976        return 0;
4977}
4978
4979static void selinux_shm_free_security(struct shmid_kernel *shp)
4980{
4981        ipc_free_security(&shp->shm_perm);
4982}
4983
4984static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
4985{
4986        struct ipc_security_struct *isec;
4987        struct common_audit_data ad;
4988        u32 sid = current_sid();
4989
4990        isec = shp->shm_perm.security;
4991
4992        COMMON_AUDIT_DATA_INIT(&ad, IPC);
4993        ad.u.ipc_id = shp->shm_perm.key;
4994
4995        return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
4996                            SHM__ASSOCIATE, &ad);
4997}
4998
4999/* Note, at this point, shp is locked down */
5000static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
5001{
5002        int perms;
5003        int err;
5004
5005        switch (cmd) {
5006        case IPC_INFO:
5007        case SHM_INFO:
5008                /* No specific object, just general system-wide information. */
5009                return task_has_system(current, SYSTEM__IPC_INFO);
5010        case IPC_STAT:
5011        case SHM_STAT:
5012                perms = SHM__GETATTR | SHM__ASSOCIATE;
5013                break;
5014        case IPC_SET:
5015                perms = SHM__SETATTR;
5016                break;
5017        case SHM_LOCK:
5018        case SHM_UNLOCK:
5019                perms = SHM__LOCK;
5020                break;
5021        case IPC_RMID:
5022                perms = SHM__DESTROY;
5023                break;
5024        default:
5025                return 0;
5026        }
5027
5028        err = ipc_has_perm(&shp->shm_perm, perms);
5029        return err;
5030}
5031
5032static int selinux_shm_shmat(struct shmid_kernel *shp,
5033                             char __user *shmaddr, int shmflg)
5034{
5035        u32 perms;
5036
5037        if (shmflg & SHM_RDONLY)
5038                perms = SHM__READ;
5039        else
5040                perms = SHM__READ | SHM__WRITE;
5041
5042        return ipc_has_perm(&shp->shm_perm, perms);
5043}
5044
5045/* Semaphore security operations */
5046static int selinux_sem_alloc_security(struct sem_array *sma)
5047{
5048        struct ipc_security_struct *isec;
5049        struct common_audit_data ad;
5050        u32 sid = current_sid();
5051        int rc;
5052
5053        rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5054        if (rc)
5055                return rc;
5056
5057        isec = sma->sem_perm.security;
5058
5059        COMMON_AUDIT_DATA_INIT(&ad, IPC);
5060        ad.u.ipc_id = sma->sem_perm.key;
5061
5062        rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5063                          SEM__CREATE, &ad);
5064        if (rc) {
5065                ipc_free_security(&sma->sem_perm);
5066                return rc;
5067        }
5068        return 0;
5069}
5070
5071static void selinux_sem_free_security(struct sem_array *sma)
5072{
5073        ipc_free_security(&sma->sem_perm);
5074}
5075
5076static int selinux_sem_associate(struct sem_array *sma, int semflg)
5077{
5078        struct ipc_security_struct *isec;
5079        struct common_audit_data ad;
5080        u32 sid = current_sid();
5081
5082        isec = sma->sem_perm.security;
5083
5084        COMMON_AUDIT_DATA_INIT(&ad, IPC);
5085        ad.u.ipc_id = sma->sem_perm.key;
5086
5087        return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5088                            SEM__ASSOCIATE, &ad);
5089}
5090
5091/* Note, at this point, sma is locked down */
5092static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5093{
5094        int err;
5095        u32 perms;
5096
5097        switch (cmd) {
5098        case IPC_INFO:
5099        case SEM_INFO:
5100                /* No specific object, just general system-wide information. */
5101                return task_has_system(current, SYSTEM__IPC_INFO);
5102        case GETPID:
5103        case GETNCNT:
5104        case GETZCNT:
5105                perms = SEM__GETATTR;
5106                break;
5107        case GETVAL:
5108        case GETALL:
5109                perms = SEM__READ;
5110                break;
5111        case SETVAL:
5112        case SETALL:
5113                perms = SEM__WRITE;
5114                break;
5115        case IPC_RMID:
5116                perms = SEM__DESTROY;
5117                break;
5118        case IPC_SET:
5119                perms = SEM__SETATTR;
5120                break;
5121        case IPC_STAT:
5122        case SEM_STAT:
5123                perms = SEM__GETATTR | SEM__ASSOCIATE;
5124                break;
5125        default:
5126                return 0;
5127        }
5128
5129        err = ipc_has_perm(&sma->sem_perm, perms);
5130        return err;
5131}
5132
5133static int selinux_sem_semop(struct sem_array *sma,
5134                             struct sembuf *sops, unsigned nsops, int alter)
5135{
5136        u32 perms;
5137
5138        if (alter)
5139                perms = SEM__READ | SEM__WRITE;
5140        else
5141                perms = SEM__READ;
5142
5143        return ipc_has_perm(&sma->sem_perm, perms);
5144}
5145
5146static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5147{
5148        u32 av = 0;
5149
5150        av = 0;
5151        if (flag & S_IRUGO)
5152                av |= IPC__UNIX_READ;
5153        if (flag & S_IWUGO)
5154                av |= IPC__UNIX_WRITE;
5155
5156        if (av == 0)
5157                return 0;
5158
5159        return ipc_has_perm(ipcp, av);
5160}
5161
5162static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5163{
5164        struct ipc_security_struct *isec = ipcp->security;
5165        *secid = isec->sid;
5166}
5167
5168static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5169{
5170        if (inode)
5171                inode_doinit_with_dentry(inode, dentry);
5172}
5173
5174static int selinux_getprocattr(struct task_struct *p,
5175                               char *name, char **value)
5176{
5177        const struct task_security_struct *__tsec;
5178        u32 sid;
5179        int error;
5180        unsigned len;
5181
5182        if (current != p) {
5183                error = current_has_perm(p, PROCESS__GETATTR);
5184                if (error)
5185                        return error;
5186        }
5187
5188        rcu_read_lock();
5189        __tsec = __task_cred(p)->security;
5190
5191        if (!strcmp(name, "current"))
5192                sid = __tsec->sid;
5193        else if (!strcmp(name, "prev"))
5194                sid = __tsec->osid;
5195        else if (!strcmp(name, "exec"))
5196                sid = __tsec->exec_sid;
5197        else if (!strcmp(name, "fscreate"))
5198                sid = __tsec->create_sid;
5199        else if (!strcmp(name, "keycreate"))
5200                sid = __tsec->keycreate_sid;
5201        else if (!strcmp(name, "sockcreate"))
5202                sid = __tsec->sockcreate_sid;
5203        else
5204                goto invalid;
5205        rcu_read_unlock();
5206
5207        if (!sid)
5208                return 0;
5209
5210        error = security_sid_to_context(sid, value, &len);
5211        if (error)
5212                return error;
5213        return len;
5214
5215invalid:
5216        rcu_read_unlock();
5217        return -EINVAL;
5218}
5219
5220static int selinux_setprocattr(struct task_struct *p,
5221                               char *name, void *value, size_t size)
5222{
5223        struct task_security_struct *tsec;
5224        struct task_struct *tracer;
5225        struct cred *new;
5226        u32 sid = 0, ptsid;
5227        int error;
5228        char *str = value;
5229
5230        if (current != p) {
5231                /* SELinux only allows a process to change its own
5232                   security attributes. */
5233                return -EACCES;
5234        }
5235
5236        /*
5237         * Basic control over ability to set these attributes at all.
5238         * current == p, but we'll pass them separately in case the
5239         * above restriction is ever removed.
5240         */
5241        if (!strcmp(name, "exec"))
5242                error = current_has_perm(p, PROCESS__SETEXEC);
5243        else if (!strcmp(name, "fscreate"))
5244                error = current_has_perm(p, PROCESS__SETFSCREATE);
5245        else if (!strcmp(name, "keycreate"))
5246                error = current_has_perm(p, PROCESS__SETKEYCREATE);
5247        else if (!strcmp(name, "sockcreate"))
5248                error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5249        else if (!strcmp(name, "current"))
5250                error = current_has_perm(p, PROCESS__SETCURRENT);
5251        else
5252                error = -EINVAL;
5253        if (error)
5254                return error;
5255
5256        /* Obtain a SID for the context, if one was specified. */
5257        if (size && str[1] && str[1] != '\n') {
5258                if (str[size-1] == '\n') {
5259                        str[size-1] = 0;
5260                        size--;
5261                }
5262                error = security_context_to_sid(value, size, &sid);
5263                if (error == -EINVAL && !strcmp(name, "fscreate")) {
5264                        if (!capable(CAP_MAC_ADMIN))
5265                                return error;
5266                        error = security_context_to_sid_force(value, size,
5267                                                              &sid);
5268                }
5269                if (error)
5270                        return error;
5271        }
5272
5273        new = prepare_creds();
5274        if (!new)
5275                return -ENOMEM;
5276
5277        /* Permission checking based on the specified context is
5278           performed during the actual operation (execve,
5279           open/mkdir/...), when we know the full context of the
5280           operation.  See selinux_bprm_set_creds for the execve
5281           checks and may_create for the file creation checks. The
5282           operation will then fail if the context is not permitted. */
5283        tsec = new->security;
5284        if (!strcmp(name, "exec")) {
5285                tsec->exec_sid = sid;
5286        } else if (!strcmp(name, "fscreate")) {
5287                tsec->create_sid = sid;
5288        } else if (!strcmp(name, "keycreate")) {
5289                error = may_create_key(sid, p);
5290                if (error)
5291                        goto abort_change;
5292                tsec->keycreate_sid = sid;
5293        } else if (!strcmp(name, "sockcreate")) {
5294                tsec->sockcreate_sid = sid;
5295        } else if (!strcmp(name, "current")) {
5296                error = -EINVAL;
5297                if (sid == 0)
5298                        goto abort_change;
5299
5300                /* Only allow single threaded processes to change context */
5301                error = -EPERM;
5302                if (!current_is_single_threaded()) {
5303                        error = security_bounded_transition(tsec->sid, sid);
5304                        if (error)
5305                                goto abort_change;
5306                }
5307
5308                /* Check permissions for the transition. */
5309                error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5310                                     PROCESS__DYNTRANSITION, NULL);
5311                if (error)
5312                        goto abort_change;
5313
5314                /* Check for ptracing, and update the task SID if ok.
5315                   Otherwise, leave SID unchanged and fail. */
5316                ptsid = 0;
5317                task_lock(p);
5318                tracer = tracehook_tracer_task(p);
5319                if (tracer)
5320                        ptsid = task_sid(tracer);
5321                task_unlock(p);
5322
5323                if (tracer) {
5324                        error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5325                                             PROCESS__PTRACE, NULL);
5326                        if (error)
5327                                goto abort_change;
5328                }
5329
5330                tsec->sid = sid;
5331        } else {
5332                error = -EINVAL;
5333                goto abort_change;
5334        }
5335
5336        commit_creds(new);
5337        return size;
5338
5339abort_change:
5340        abort_creds(new);
5341        return error;
5342}
5343
5344static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5345{
5346        return security_sid_to_context(secid, secdata, seclen);
5347}
5348
5349static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5350{
5351        return security_context_to_sid(secdata, seclen, secid);
5352}
5353
5354static void selinux_release_secctx(char *secdata, u32 seclen)
5355{
5356        kfree(secdata);
5357}
5358
5359/*
5360 *      called with inode->i_mutex locked
5361 */
5362static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5363{
5364        return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5365}
5366
5367/*
5368 *      called with inode->i_mutex locked
5369 */
5370static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5371{
5372        return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5373}
5374
5375static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5376{
5377        int len = 0;
5378        len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5379                                                ctx, true);
5380        if (len < 0)
5381                return len;
5382        *ctxlen = len;
5383        return 0;
5384}
5385#ifdef CONFIG_KEYS
5386
5387static int selinux_key_alloc(struct key *k, const struct cred *cred,
5388                             unsigned long flags)
5389{
5390        const struct task_security_struct *tsec;
5391        struct key_security_struct *ksec;
5392
5393        ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5394        if (!ksec)
5395                return -ENOMEM;
5396
5397        tsec = cred->security;
5398        if (tsec->keycreate_sid)
5399                ksec->sid = tsec->keycreate_sid;
5400        else
5401                ksec->sid = tsec->sid;
5402
5403        k->security = ksec;
5404        return 0;
5405}
5406
5407static void selinux_key_free(struct key *k)
5408{
5409        struct key_security_struct *ksec = k->security;
5410
5411        k->security = NULL;
5412        kfree(ksec);
5413}
5414
5415static int selinux_key_permission(key_ref_t key_ref,
5416                                  const struct cred *cred,
5417                                  key_perm_t perm)
5418{
5419        struct key *key;
5420        struct key_security_struct *ksec;
5421        u32 sid;
5422
5423        /* if no specific permissions are requested, we skip the
5424           permission check. No serious, additional covert channels
5425           appear to be created. */
5426        if (perm == 0)
5427                return 0;
5428
5429        sid = cred_sid(cred);
5430
5431        key = key_ref_to_ptr(key_ref);
5432        ksec = key->security;
5433
5434        return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5435}
5436
5437static int selinux_key_getsecurity(struct key *key, char **_buffer)
5438{
5439        struct key_security_struct *ksec = key->security;
5440        char *context = NULL;
5441        unsigned len;
5442        int rc;
5443
5444        rc = security_sid_to_context(ksec->sid, &context, &len);
5445        if (!rc)
5446                rc = len;
5447        *_buffer = context;
5448        return rc;
5449}
5450
5451#endif
5452
5453static struct security_operations selinux_ops = {
5454        .name =                         "selinux",
5455
5456        .ptrace_access_check =          selinux_ptrace_access_check,
5457        .ptrace_traceme =               selinux_ptrace_traceme,
5458        .capget =                       selinux_capget,
5459        .capset =                       selinux_capset,
5460        .sysctl =                       selinux_sysctl,
5461        .capable =                      selinux_capable,
5462        .quotactl =                     selinux_quotactl,
5463        .quota_on =                     selinux_quota_on,
5464        .syslog =                       selinux_syslog,
5465        .vm_enough_memory =             selinux_vm_enough_memory,
5466
5467        .netlink_send =                 selinux_netlink_send,
5468        .netlink_recv =                 selinux_netlink_recv,
5469
5470        .bprm_set_creds =               selinux_bprm_set_creds,
5471        .bprm_committing_creds =        selinux_bprm_committing_creds,
5472        .bprm_committed_creds =         selinux_bprm_committed_creds,
5473        .bprm_secureexec =              selinux_bprm_secureexec,
5474
5475        .sb_alloc_security =            selinux_sb_alloc_security,
5476        .sb_free_security =             selinux_sb_free_security,
5477        .sb_copy_data =                 selinux_sb_copy_data,
5478        .sb_kern_mount =                selinux_sb_kern_mount,
5479        .sb_show_options =              selinux_sb_show_options,
5480        .sb_statfs =                    selinux_sb_statfs,
5481        .sb_mount =                     selinux_mount,
5482        .sb_umount =                    selinux_umount,
5483        .sb_set_mnt_opts =              selinux_set_mnt_opts,
5484        .sb_clone_mnt_opts =            selinux_sb_clone_mnt_opts,
5485        .sb_parse_opts_str =            selinux_parse_opts_str,
5486
5487
5488        .inode_alloc_security =         selinux_inode_alloc_security,
5489        .inode_free_security =          selinux_inode_free_security,
5490        .inode_init_security =          selinux_inode_init_security,
5491        .inode_create =                 selinux_inode_create,
5492        .inode_link =                   selinux_inode_link,
5493        .inode_unlink =                 selinux_inode_unlink,
5494        .inode_symlink =                selinux_inode_symlink,
5495        .inode_mkdir =                  selinux_inode_mkdir,
5496        .inode_rmdir =                  selinux_inode_rmdir,
5497        .inode_mknod =                  selinux_inode_mknod,
5498        .inode_rename =                 selinux_inode_rename,
5499        .inode_readlink =               selinux_inode_readlink,
5500        .inode_follow_link =            selinux_inode_follow_link,
5501        .inode_permission =             selinux_inode_permission,
5502        .inode_setattr =                selinux_inode_setattr,
5503        .inode_getattr =                selinux_inode_getattr,
5504        .inode_setxattr =               selinux_inode_setxattr,
5505        .inode_post_setxattr =          selinux_inode_post_setxattr,
5506        .inode_getxattr =               selinux_inode_getxattr,
5507        .inode_listxattr =              selinux_inode_listxattr,
5508        .inode_removexattr =            selinux_inode_removexattr,
5509        .inode_getsecurity =            selinux_inode_getsecurity,
5510        .inode_setsecurity =            selinux_inode_setsecurity,
5511        .inode_listsecurity =           selinux_inode_listsecurity,
5512        .inode_getsecid =               selinux_inode_getsecid,
5513
5514        .file_permission =              selinux_file_permission,
5515        .file_alloc_security =          selinux_file_alloc_security,
5516        .file_free_security =           selinux_file_free_security,
5517        .file_ioctl =                   selinux_file_ioctl,
5518        .file_mmap =                    selinux_file_mmap,
5519        .file_mprotect =                selinux_file_mprotect,
5520        .file_lock =                    selinux_file_lock,
5521        .file_fcntl =                   selinux_file_fcntl,
5522        .file_set_fowner =              selinux_file_set_fowner,
5523        .file_send_sigiotask =          selinux_file_send_sigiotask,
5524        .file_receive =                 selinux_file_receive,
5525
5526        .dentry_open =                  selinux_dentry_open,
5527
5528        .task_create =                  selinux_task_create,
5529        .cred_alloc_blank =             selinux_cred_alloc_blank,
5530        .cred_free =                    selinux_cred_free,
5531        .cred_prepare =                 selinux_cred_prepare,
5532        .cred_transfer =                selinux_cred_transfer,
5533        .kernel_act_as =                selinux_kernel_act_as,
5534        .kernel_create_files_as =       selinux_kernel_create_files_as,
5535        .kernel_module_request =        selinux_kernel_module_request,
5536        .task_setpgid =                 selinux_task_setpgid,
5537        .task_getpgid =                 selinux_task_getpgid,
5538        .task_getsid =                  selinux_task_getsid,
5539        .task_getsecid =                selinux_task_getsecid,
5540        .task_setnice =                 selinux_task_setnice,
5541        .task_setioprio =               selinux_task_setioprio,
5542        .task_getioprio =               selinux_task_getioprio,
5543        .task_setrlimit =               selinux_task_setrlimit,
5544        .task_setscheduler =            selinux_task_setscheduler,
5545        .task_getscheduler =            selinux_task_getscheduler,
5546        .task_movememory =              selinux_task_movememory,
5547        .task_kill =                    selinux_task_kill,
5548        .task_wait =                    selinux_task_wait,