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47#include <linux/mm.h>
48#include <linux/shm.h>
49#include <linux/init.h>
50#include <linux/msg.h>
51#include <linux/vmalloc.h>
52#include <linux/slab.h>
53#include <linux/notifier.h>
54#include <linux/capability.h>
55#include <linux/highuid.h>
56#include <linux/security.h>
57#include <linux/rcupdate.h>
58#include <linux/workqueue.h>
59#include <linux/seq_file.h>
60#include <linux/proc_fs.h>
61#include <linux/audit.h>
62#include <linux/nsproxy.h>
63#include <linux/rwsem.h>
64#include <linux/memory.h>
65#include <linux/ipc_namespace.h>
66
67#include <asm/unistd.h>
68
69#include "util.h"
70
71struct ipc_proc_iface {
72 const char *path;
73 const char *header;
74 int ids;
75 int (*show)(struct seq_file *, void *);
76};
77
78
79
80
81
82
83
84
85
86
87
88static int __init ipc_init(void)
89{
90 int err_sem, err_msg;
91
92 proc_mkdir("sysvipc", NULL);
93 err_sem = sem_init();
94 WARN(err_sem, "ipc: sysv sem_init failed: %d\n", err_sem);
95 err_msg = msg_init();
96 WARN(err_msg, "ipc: sysv msg_init failed: %d\n", err_msg);
97 shm_init();
98
99 return err_msg ? err_msg : err_sem;
100}
101device_initcall(ipc_init);
102
103static const struct rhashtable_params ipc_kht_params = {
104 .head_offset = offsetof(struct kern_ipc_perm, khtnode),
105 .key_offset = offsetof(struct kern_ipc_perm, key),
106 .key_len = FIELD_SIZEOF(struct kern_ipc_perm, key),
107 .locks_mul = 1,
108 .automatic_shrinking = true,
109};
110
111
112
113
114
115
116
117
118int ipc_init_ids(struct ipc_ids *ids)
119{
120 int err;
121 ids->in_use = 0;
122 ids->seq = 0;
123 init_rwsem(&ids->rwsem);
124 err = rhashtable_init(&ids->key_ht, &ipc_kht_params);
125 if (err)
126 return err;
127 idr_init(&ids->ipcs_idr);
128 ids->tables_initialized = true;
129 ids->max_id = -1;
130#ifdef CONFIG_CHECKPOINT_RESTORE
131 ids->next_id = -1;
132#endif
133 return 0;
134}
135
136#ifdef CONFIG_PROC_FS
137static const struct file_operations sysvipc_proc_fops;
138
139
140
141
142
143
144
145void __init ipc_init_proc_interface(const char *path, const char *header,
146 int ids, int (*show)(struct seq_file *, void *))
147{
148 struct proc_dir_entry *pde;
149 struct ipc_proc_iface *iface;
150
151 iface = kmalloc(sizeof(*iface), GFP_KERNEL);
152 if (!iface)
153 return;
154 iface->path = path;
155 iface->header = header;
156 iface->ids = ids;
157 iface->show = show;
158
159 pde = proc_create_data(path,
160 S_IRUGO,
161 NULL,
162 &sysvipc_proc_fops,
163 iface);
164 if (!pde)
165 kfree(iface);
166}
167#endif
168
169
170
171
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176
177
178
179static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
180{
181 struct kern_ipc_perm *ipcp = NULL;
182
183 if (likely(ids->tables_initialized))
184 ipcp = rhashtable_lookup_fast(&ids->key_ht, &key,
185 ipc_kht_params);
186
187 if (ipcp) {
188 rcu_read_lock();
189 ipc_lock_object(ipcp);
190 return ipcp;
191 }
192
193 return NULL;
194}
195
196#ifdef CONFIG_CHECKPOINT_RESTORE
197
198
199
200#define ipc_idr_alloc(ids, new) \
201 idr_alloc(&(ids)->ipcs_idr, (new), \
202 (ids)->next_id < 0 ? 0 : ipcid_to_idx((ids)->next_id),\
203 0, GFP_NOWAIT)
204
205static inline int ipc_buildid(int id, struct ipc_ids *ids,
206 struct kern_ipc_perm *new)
207{
208 if (ids->next_id < 0) {
209 new->seq = ids->seq++;
210 if (ids->seq > IPCID_SEQ_MAX)
211 ids->seq = 0;
212 } else {
213 new->seq = ipcid_to_seqx(ids->next_id);
214 ids->next_id = -1;
215 }
216
217 return SEQ_MULTIPLIER * new->seq + id;
218}
219
220#else
221#define ipc_idr_alloc(ids, new) \
222 idr_alloc(&(ids)->ipcs_idr, (new), 0, 0, GFP_NOWAIT)
223
224static inline int ipc_buildid(int id, struct ipc_ids *ids,
225 struct kern_ipc_perm *new)
226{
227 new->seq = ids->seq++;
228 if (ids->seq > IPCID_SEQ_MAX)
229 ids->seq = 0;
230
231 return SEQ_MULTIPLIER * new->seq + id;
232}
233
234#endif
235
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246
247
248
249int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int limit)
250{
251 kuid_t euid;
252 kgid_t egid;
253 int id, err;
254
255 if (limit > IPCMNI)
256 limit = IPCMNI;
257
258 if (!ids->tables_initialized || ids->in_use >= limit)
259 return -ENOSPC;
260
261 idr_preload(GFP_KERNEL);
262
263 refcount_set(&new->refcount, 1);
264 spin_lock_init(&new->lock);
265 new->deleted = false;
266 rcu_read_lock();
267 spin_lock(&new->lock);
268
269 current_euid_egid(&euid, &egid);
270 new->cuid = new->uid = euid;
271 new->gid = new->cgid = egid;
272
273 id = ipc_idr_alloc(ids, new);
274 idr_preload_end();
275
276 if (id >= 0 && new->key != IPC_PRIVATE) {
277 err = rhashtable_insert_fast(&ids->key_ht, &new->khtnode,
278 ipc_kht_params);
279 if (err < 0) {
280 idr_remove(&ids->ipcs_idr, id);
281 id = err;
282 }
283 }
284 if (id < 0) {
285 spin_unlock(&new->lock);
286 rcu_read_unlock();
287 return id;
288 }
289
290 ids->in_use++;
291 if (id > ids->max_id)
292 ids->max_id = id;
293
294 new->id = ipc_buildid(id, ids, new);
295
296 return id;
297}
298
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307
308
309static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
310 const struct ipc_ops *ops, struct ipc_params *params)
311{
312 int err;
313
314 down_write(&ids->rwsem);
315 err = ops->getnew(ns, params);
316 up_write(&ids->rwsem);
317 return err;
318}
319
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334
335static int ipc_check_perms(struct ipc_namespace *ns,
336 struct kern_ipc_perm *ipcp,
337 const struct ipc_ops *ops,
338 struct ipc_params *params)
339{
340 int err;
341
342 if (ipcperms(ns, ipcp, params->flg))
343 err = -EACCES;
344 else {
345 err = ops->associate(ipcp, params->flg);
346 if (!err)
347 err = ipcp->id;
348 }
349
350 return err;
351}
352
353
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364
365
366
367static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
368 const struct ipc_ops *ops, struct ipc_params *params)
369{
370 struct kern_ipc_perm *ipcp;
371 int flg = params->flg;
372 int err;
373
374
375
376
377
378 down_write(&ids->rwsem);
379 ipcp = ipc_findkey(ids, params->key);
380 if (ipcp == NULL) {
381
382 if (!(flg & IPC_CREAT))
383 err = -ENOENT;
384 else
385 err = ops->getnew(ns, params);
386 } else {
387
388
389 if (flg & IPC_CREAT && flg & IPC_EXCL)
390 err = -EEXIST;
391 else {
392 err = 0;
393 if (ops->more_checks)
394 err = ops->more_checks(ipcp, params);
395 if (!err)
396
397
398
399
400 err = ipc_check_perms(ns, ipcp, ops, params);
401 }
402 ipc_unlock(ipcp);
403 }
404 up_write(&ids->rwsem);
405
406 return err;
407}
408
409
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411
412
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415
416
417static void ipc_kht_remove(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
418{
419 if (ipcp->key != IPC_PRIVATE)
420 rhashtable_remove_fast(&ids->key_ht, &ipcp->khtnode,
421 ipc_kht_params);
422}
423
424
425
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429
430
431
432void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
433{
434 int lid = ipcid_to_idx(ipcp->id);
435
436 idr_remove(&ids->ipcs_idr, lid);
437 ipc_kht_remove(ids, ipcp);
438 ids->in_use--;
439 ipcp->deleted = true;
440
441 if (unlikely(lid == ids->max_id)) {
442 do {
443 lid--;
444 if (lid == -1)
445 break;
446 } while (!idr_find(&ids->ipcs_idr, lid));
447 ids->max_id = lid;
448 }
449}
450
451
452
453
454
455
456
457
458
459void ipc_set_key_private(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
460{
461 ipc_kht_remove(ids, ipcp);
462 ipcp->key = IPC_PRIVATE;
463}
464
465int ipc_rcu_getref(struct kern_ipc_perm *ptr)
466{
467 return refcount_inc_not_zero(&ptr->refcount);
468}
469
470void ipc_rcu_putref(struct kern_ipc_perm *ptr,
471 void (*func)(struct rcu_head *head))
472{
473 if (!refcount_dec_and_test(&ptr->refcount))
474 return;
475
476 call_rcu(&ptr->rcu, func);
477}
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488
489
490int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
491{
492 kuid_t euid = current_euid();
493 int requested_mode, granted_mode;
494
495 audit_ipc_obj(ipcp);
496 requested_mode = (flag >> 6) | (flag >> 3) | flag;
497 granted_mode = ipcp->mode;
498 if (uid_eq(euid, ipcp->cuid) ||
499 uid_eq(euid, ipcp->uid))
500 granted_mode >>= 6;
501 else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
502 granted_mode >>= 3;
503
504 if ((requested_mode & ~granted_mode & 0007) &&
505 !ns_capable(ns->user_ns, CAP_IPC_OWNER))
506 return -1;
507
508 return security_ipc_permission(ipcp, flag);
509}
510
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522
523
524void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
525{
526 out->key = in->key;
527 out->uid = from_kuid_munged(current_user_ns(), in->uid);
528 out->gid = from_kgid_munged(current_user_ns(), in->gid);
529 out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
530 out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
531 out->mode = in->mode;
532 out->seq = in->seq;
533}
534
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537
538
539
540
541
542
543void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
544{
545 out->key = in->key;
546 SET_UID(out->uid, in->uid);
547 SET_GID(out->gid, in->gid);
548 SET_UID(out->cuid, in->cuid);
549 SET_GID(out->cgid, in->cgid);
550 out->mode = in->mode;
551 out->seq = in->seq;
552}
553
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562
563
564struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id)
565{
566 struct kern_ipc_perm *out;
567 int lid = ipcid_to_idx(id);
568
569 if (unlikely(!ids->tables_initialized))
570 return ERR_PTR(-EINVAL);
571
572 out = idr_find(&ids->ipcs_idr, lid);
573 if (!out)
574 return ERR_PTR(-EINVAL);
575
576 return out;
577}
578
579
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581
582
583
584
585
586
587
588struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
589{
590 struct kern_ipc_perm *out;
591
592 rcu_read_lock();
593 out = ipc_obtain_object_idr(ids, id);
594 if (IS_ERR(out))
595 goto err;
596
597 spin_lock(&out->lock);
598
599
600
601
602
603
604
605 if (ipc_valid_object(out))
606 return out;
607
608 spin_unlock(&out->lock);
609 out = ERR_PTR(-EIDRM);
610err:
611 rcu_read_unlock();
612 return out;
613}
614
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619
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623
624
625
626struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
627{
628 struct kern_ipc_perm *out = ipc_obtain_object_idr(ids, id);
629
630 if (IS_ERR(out))
631 goto out;
632
633 if (ipc_checkid(out, id))
634 return ERR_PTR(-EINVAL);
635out:
636 return out;
637}
638
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647
648
649int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
650 const struct ipc_ops *ops, struct ipc_params *params)
651{
652 if (params->key == IPC_PRIVATE)
653 return ipcget_new(ns, ids, ops, params);
654 else
655 return ipcget_public(ns, ids, ops, params);
656}
657
658
659
660
661
662
663int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
664{
665 kuid_t uid = make_kuid(current_user_ns(), in->uid);
666 kgid_t gid = make_kgid(current_user_ns(), in->gid);
667 if (!uid_valid(uid) || !gid_valid(gid))
668 return -EINVAL;
669
670 out->uid = uid;
671 out->gid = gid;
672 out->mode = (out->mode & ~S_IRWXUGO)
673 | (in->mode & S_IRWXUGO);
674
675 return 0;
676}
677
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698struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
699 struct ipc_ids *ids, int id, int cmd,
700 struct ipc64_perm *perm, int extra_perm)
701{
702 kuid_t euid;
703 int err = -EPERM;
704 struct kern_ipc_perm *ipcp;
705
706 ipcp = ipc_obtain_object_check(ids, id);
707 if (IS_ERR(ipcp)) {
708 err = PTR_ERR(ipcp);
709 goto err;
710 }
711
712 audit_ipc_obj(ipcp);
713 if (cmd == IPC_SET)
714 audit_ipc_set_perm(extra_perm, perm->uid,
715 perm->gid, perm->mode);
716
717 euid = current_euid();
718 if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
719 ns_capable(ns->user_ns, CAP_SYS_ADMIN))
720 return ipcp;
721err:
722 return ERR_PTR(err);
723}
724
725#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
726
727
728
729
730
731
732
733
734
735
736int ipc_parse_version(int *cmd)
737{
738 if (*cmd & IPC_64) {
739 *cmd ^= IPC_64;
740 return IPC_64;
741 } else {
742 return IPC_OLD;
743 }
744}
745
746#endif
747
748#ifdef CONFIG_PROC_FS
749struct ipc_proc_iter {
750 struct ipc_namespace *ns;
751 struct pid_namespace *pid_ns;
752 struct ipc_proc_iface *iface;
753};
754
755struct pid_namespace *ipc_seq_pid_ns(struct seq_file *s)
756{
757 struct ipc_proc_iter *iter = s->private;
758 return iter->pid_ns;
759}
760
761
762
763
764static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
765 loff_t *new_pos)
766{
767 struct kern_ipc_perm *ipc;
768 int total, id;
769
770 total = 0;
771 for (id = 0; id < pos && total < ids->in_use; id++) {
772 ipc = idr_find(&ids->ipcs_idr, id);
773 if (ipc != NULL)
774 total++;
775 }
776
777 if (total >= ids->in_use)
778 return NULL;
779
780 for (; pos < IPCMNI; pos++) {
781 ipc = idr_find(&ids->ipcs_idr, pos);
782 if (ipc != NULL) {
783 *new_pos = pos + 1;
784 rcu_read_lock();
785 ipc_lock_object(ipc);
786 return ipc;
787 }
788 }
789
790
791 return NULL;
792}
793
794static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
795{
796 struct ipc_proc_iter *iter = s->private;
797 struct ipc_proc_iface *iface = iter->iface;
798 struct kern_ipc_perm *ipc = it;
799
800
801 if (ipc && ipc != SEQ_START_TOKEN)
802 ipc_unlock(ipc);
803
804 return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
805}
806
807
808
809
810
811static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
812{
813 struct ipc_proc_iter *iter = s->private;
814 struct ipc_proc_iface *iface = iter->iface;
815 struct ipc_ids *ids;
816
817 ids = &iter->ns->ids[iface->ids];
818
819
820
821
822
823 down_read(&ids->rwsem);
824
825
826 if (*pos < 0)
827 return NULL;
828
829
830 if (*pos == 0)
831 return SEQ_START_TOKEN;
832
833
834 return sysvipc_find_ipc(ids, *pos - 1, pos);
835}
836
837static void sysvipc_proc_stop(struct seq_file *s, void *it)
838{
839 struct kern_ipc_perm *ipc = it;
840 struct ipc_proc_iter *iter = s->private;
841 struct ipc_proc_iface *iface = iter->iface;
842 struct ipc_ids *ids;
843
844
845 if (ipc && ipc != SEQ_START_TOKEN)
846 ipc_unlock(ipc);
847
848 ids = &iter->ns->ids[iface->ids];
849
850 up_read(&ids->rwsem);
851}
852
853static int sysvipc_proc_show(struct seq_file *s, void *it)
854{
855 struct ipc_proc_iter *iter = s->private;
856 struct ipc_proc_iface *iface = iter->iface;
857
858 if (it == SEQ_START_TOKEN) {
859 seq_puts(s, iface->header);
860 return 0;
861 }
862
863 return iface->show(s, it);
864}
865
866static const struct seq_operations sysvipc_proc_seqops = {
867 .start = sysvipc_proc_start,
868 .stop = sysvipc_proc_stop,
869 .next = sysvipc_proc_next,
870 .show = sysvipc_proc_show,
871};
872
873static int sysvipc_proc_open(struct inode *inode, struct file *file)
874{
875 struct ipc_proc_iter *iter;
876
877 iter = __seq_open_private(file, &sysvipc_proc_seqops, sizeof(*iter));
878 if (!iter)
879 return -ENOMEM;
880
881 iter->iface = PDE_DATA(inode);
882 iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
883 iter->pid_ns = get_pid_ns(task_active_pid_ns(current));
884
885 return 0;
886}
887
888static int sysvipc_proc_release(struct inode *inode, struct file *file)
889{
890 struct seq_file *seq = file->private_data;
891 struct ipc_proc_iter *iter = seq->private;
892 put_ipc_ns(iter->ns);
893 put_pid_ns(iter->pid_ns);
894 return seq_release_private(inode, file);
895}
896
897static const struct file_operations sysvipc_proc_fops = {
898 .open = sysvipc_proc_open,
899 .read = seq_read,
900 .llseek = seq_lseek,
901 .release = sysvipc_proc_release,
902};
903#endif
904