LXR linux/security/tomoyo/environ.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * security/tomoyo/environ.c
   4 *
   5 * Copyright (C) 2005-2011  NTT DATA CORPORATION
   6 */
   7
   8#include "common.h"
   9
  10/**
  11 * tomoyo_check_env_acl - Check permission for environment variable's name.
  12 *
  13 * @r:   Pointer to "struct tomoyo_request_info".
  14 * @ptr: Pointer to "struct tomoyo_acl_info".
  15 *
  16 * Returns true if granted, false otherwise.
  17 */
  18static bool tomoyo_check_env_acl(struct tomoyo_request_info *r,
  19                                 const struct tomoyo_acl_info *ptr)
  20{
  21        const struct tomoyo_env_acl *acl =
  22                container_of(ptr, typeof(*acl), head);
  23
  24        return tomoyo_path_matches_pattern(r->param.environ.name, acl->env);
  25}
  26
  27/**
  28 * tomoyo_audit_env_log - Audit environment variable name log.
  29 *
  30 * @r: Pointer to "struct tomoyo_request_info".
  31 *
  32 * Returns 0 on success, negative value otherwise.
  33 */
  34static int tomoyo_audit_env_log(struct tomoyo_request_info *r)
  35{
  36        return tomoyo_supervisor(r, "misc env %s\n",
  37                                 r->param.environ.name->name);
  38}
  39
  40/**
  41 * tomoyo_env_perm - Check permission for environment variable's name.
  42 *
  43 * @r:   Pointer to "struct tomoyo_request_info".
  44 * @env: The name of environment variable.
  45 *
  46 * Returns 0 on success, negative value otherwise.
  47 *
  48 * Caller holds tomoyo_read_lock().
  49 */
  50int tomoyo_env_perm(struct tomoyo_request_info *r, const char *env)
  51{
  52        struct tomoyo_path_info environ;
  53        int error;
  54
  55        if (!env || !*env)
  56                return 0;
  57        environ.name = env;
  58        tomoyo_fill_path_info(&environ);
  59        r->param_type = TOMOYO_TYPE_ENV_ACL;
  60        r->param.environ.name = &environ;
  61        do {
  62                tomoyo_check_acl(r, tomoyo_check_env_acl);
  63                error = tomoyo_audit_env_log(r);
  64        } while (error == TOMOYO_RETRY_REQUEST);
  65        return error;
  66}
  67
  68/**
  69 * tomoyo_same_env_acl - Check for duplicated "struct tomoyo_env_acl" entry.
  70 *
  71 * @a: Pointer to "struct tomoyo_acl_info".
  72 * @b: Pointer to "struct tomoyo_acl_info".
  73 *
  74 * Returns true if @a == @b, false otherwise.
  75 */
  76static bool tomoyo_same_env_acl(const struct tomoyo_acl_info *a,
  77                                const struct tomoyo_acl_info *b)
  78{
  79        const struct tomoyo_env_acl *p1 = container_of(a, typeof(*p1), head);
  80        const struct tomoyo_env_acl *p2 = container_of(b, typeof(*p2), head);
  81
  82        return p1->env == p2->env;
  83}
  84
  85/**
  86 * tomoyo_write_env - Write "struct tomoyo_env_acl" list.
  87 *
  88 * @param: Pointer to "struct tomoyo_acl_param".
  89 *
  90 * Returns 0 on success, negative value otherwise.
  91 *
  92 * Caller holds tomoyo_read_lock().
  93 */
  94static int tomoyo_write_env(struct tomoyo_acl_param *param)
  95{
  96        struct tomoyo_env_acl e = { .head.type = TOMOYO_TYPE_ENV_ACL };
  97        int error = -ENOMEM;
  98        const char *data = tomoyo_read_token(param);
  99
 100        if (!tomoyo_correct_word(data) || strchr(data, '='))
 101                return -EINVAL;
 102        e.env = tomoyo_get_name(data);
 103        if (!e.env)
 104                return error;
 105        error = tomoyo_update_domain(&e.head, sizeof(e), param,
 106                                  tomoyo_same_env_acl, NULL);
 107        tomoyo_put_name(e.env);
 108        return error;
 109}
 110
 111/**
 112 * tomoyo_write_misc - Update environment variable list.
 113 *
 114 * @param: Pointer to "struct tomoyo_acl_param".
 115 *
 116 * Returns 0 on success, negative value otherwise.
 117 */
 118int tomoyo_write_misc(struct tomoyo_acl_param *param)
 119{
 120        if (tomoyo_str_starts(&param->data, "env "))
 121                return tomoyo_write_env(param);
 122        return -EINVAL;
 123}
 124