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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#include <linux/rhashtable.h>
67#include <linux/log2.h>
68
69#include <asm/unistd.h>
70
71#include "util.h"
72
73struct ipc_proc_iface {
74 const char *path;
75 const char *header;
76 int ids;
77 int (*show)(struct seq_file *, void *);
78};
79
80
81
82
83
84
85
86
87
88
89
90static int __init ipc_init(void)
91{
92 proc_mkdir("sysvipc", NULL);
93 sem_init();
94 msg_init();
95 shm_init();
96
97 return 0;
98}
99device_initcall(ipc_init);
100
101static const struct rhashtable_params ipc_kht_params = {
102 .head_offset = offsetof(struct kern_ipc_perm, khtnode),
103 .key_offset = offsetof(struct kern_ipc_perm, key),
104 .key_len = sizeof_field(struct kern_ipc_perm, key),
105 .automatic_shrinking = true,
106};
107
108
109
110
111
112
113
114
115void ipc_init_ids(struct ipc_ids *ids)
116{
117 ids->in_use = 0;
118 ids->seq = 0;
119 init_rwsem(&ids->rwsem);
120 rhashtable_init(&ids->key_ht, &ipc_kht_params);
121 idr_init(&ids->ipcs_idr);
122 ids->max_idx = -1;
123 ids->last_idx = -1;
124#ifdef CONFIG_CHECKPOINT_RESTORE
125 ids->next_id = -1;
126#endif
127}
128
129#ifdef CONFIG_PROC_FS
130static const struct proc_ops sysvipc_proc_ops;
131
132
133
134
135
136
137
138void __init ipc_init_proc_interface(const char *path, const char *header,
139 int ids, int (*show)(struct seq_file *, void *))
140{
141 struct proc_dir_entry *pde;
142 struct ipc_proc_iface *iface;
143
144 iface = kmalloc(sizeof(*iface), GFP_KERNEL);
145 if (!iface)
146 return;
147 iface->path = path;
148 iface->header = header;
149 iface->ids = ids;
150 iface->show = show;
151
152 pde = proc_create_data(path,
153 S_IRUGO,
154 NULL,
155 &sysvipc_proc_ops,
156 iface);
157 if (!pde)
158 kfree(iface);
159}
160#endif
161
162
163
164
165
166
167
168
169
170
171
172static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
173{
174 struct kern_ipc_perm *ipcp;
175
176 ipcp = rhashtable_lookup_fast(&ids->key_ht, &key,
177 ipc_kht_params);
178 if (!ipcp)
179 return NULL;
180
181 rcu_read_lock();
182 ipc_lock_object(ipcp);
183 return ipcp;
184}
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200
201
202static inline int ipc_idr_alloc(struct ipc_ids *ids, struct kern_ipc_perm *new)
203{
204 int idx, next_id = -1;
205
206#ifdef CONFIG_CHECKPOINT_RESTORE
207 next_id = ids->next_id;
208 ids->next_id = -1;
209#endif
210
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217
218
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220
221
222
223 if (next_id < 0) {
224 int max_idx;
225
226 max_idx = max(ids->in_use*3/2, ipc_min_cycle);
227 max_idx = min(max_idx, ipc_mni);
228
229
230 idx = idr_alloc_cyclic(&ids->ipcs_idr, NULL, 0, max_idx,
231 GFP_NOWAIT);
232
233 if (idx >= 0) {
234
235
236
237
238
239 if (idx <= ids->last_idx) {
240 ids->seq++;
241 if (ids->seq >= ipcid_seq_max())
242 ids->seq = 0;
243 }
244 ids->last_idx = idx;
245
246 new->seq = ids->seq;
247
248
249
250
251 idr_replace(&ids->ipcs_idr, new, idx);
252 }
253 } else {
254 new->seq = ipcid_to_seqx(next_id);
255 idx = idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id),
256 0, GFP_NOWAIT);
257 }
258 if (idx >= 0)
259 new->id = (new->seq << ipcmni_seq_shift()) + idx;
260 return idx;
261}
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276
277
278int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int limit)
279{
280 kuid_t euid;
281 kgid_t egid;
282 int idx, err;
283
284
285 refcount_set(&new->refcount, 1);
286
287 if (limit > ipc_mni)
288 limit = ipc_mni;
289
290 if (ids->in_use >= limit)
291 return -ENOSPC;
292
293 idr_preload(GFP_KERNEL);
294
295 spin_lock_init(&new->lock);
296 rcu_read_lock();
297 spin_lock(&new->lock);
298
299 current_euid_egid(&euid, &egid);
300 new->cuid = new->uid = euid;
301 new->gid = new->cgid = egid;
302
303 new->deleted = false;
304
305 idx = ipc_idr_alloc(ids, new);
306 idr_preload_end();
307
308 if (idx >= 0 && new->key != IPC_PRIVATE) {
309 err = rhashtable_insert_fast(&ids->key_ht, &new->khtnode,
310 ipc_kht_params);
311 if (err < 0) {
312 idr_remove(&ids->ipcs_idr, idx);
313 idx = err;
314 }
315 }
316 if (idx < 0) {
317 new->deleted = true;
318 spin_unlock(&new->lock);
319 rcu_read_unlock();
320 return idx;
321 }
322
323 ids->in_use++;
324 if (idx > ids->max_idx)
325 ids->max_idx = idx;
326 return idx;
327}
328
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337
338
339static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
340 const struct ipc_ops *ops, struct ipc_params *params)
341{
342 int err;
343
344 down_write(&ids->rwsem);
345 err = ops->getnew(ns, params);
346 up_write(&ids->rwsem);
347 return err;
348}
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364
365static int ipc_check_perms(struct ipc_namespace *ns,
366 struct kern_ipc_perm *ipcp,
367 const struct ipc_ops *ops,
368 struct ipc_params *params)
369{
370 int err;
371
372 if (ipcperms(ns, ipcp, params->flg))
373 err = -EACCES;
374 else {
375 err = ops->associate(ipcp, params->flg);
376 if (!err)
377 err = ipcp->id;
378 }
379
380 return err;
381}
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396
397static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
398 const struct ipc_ops *ops, struct ipc_params *params)
399{
400 struct kern_ipc_perm *ipcp;
401 int flg = params->flg;
402 int err;
403
404
405
406
407
408 down_write(&ids->rwsem);
409 ipcp = ipc_findkey(ids, params->key);
410 if (ipcp == NULL) {
411
412 if (!(flg & IPC_CREAT))
413 err = -ENOENT;
414 else
415 err = ops->getnew(ns, params);
416 } else {
417
418
419 if (flg & IPC_CREAT && flg & IPC_EXCL)
420 err = -EEXIST;
421 else {
422 err = 0;
423 if (ops->more_checks)
424 err = ops->more_checks(ipcp, params);
425 if (!err)
426
427
428
429
430 err = ipc_check_perms(ns, ipcp, ops, params);
431 }
432 ipc_unlock(ipcp);
433 }
434 up_write(&ids->rwsem);
435
436 return err;
437}
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446
447static void ipc_kht_remove(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
448{
449 if (ipcp->key != IPC_PRIVATE)
450 WARN_ON_ONCE(rhashtable_remove_fast(&ids->key_ht, &ipcp->khtnode,
451 ipc_kht_params));
452}
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466
467static int ipc_search_maxidx(struct ipc_ids *ids, int limit)
468{
469 int tmpidx;
470 int i;
471 int retval;
472
473 i = ilog2(limit+1);
474
475 retval = 0;
476 for (; i >= 0; i--) {
477 tmpidx = retval | (1<<i);
478
479
480
481
482 tmpidx = tmpidx-1;
483 if (idr_get_next(&ids->ipcs_idr, &tmpidx))
484 retval |= (1<<i);
485 }
486 return retval - 1;
487}
488
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495
496
497void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
498{
499 int idx = ipcid_to_idx(ipcp->id);
500
501 WARN_ON_ONCE(idr_remove(&ids->ipcs_idr, idx) != ipcp);
502 ipc_kht_remove(ids, ipcp);
503 ids->in_use--;
504 ipcp->deleted = true;
505
506 if (unlikely(idx == ids->max_idx)) {
507 idx = ids->max_idx-1;
508 if (idx >= 0)
509 idx = ipc_search_maxidx(ids, idx);
510 ids->max_idx = idx;
511 }
512}
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519
520
521
522void ipc_set_key_private(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
523{
524 ipc_kht_remove(ids, ipcp);
525 ipcp->key = IPC_PRIVATE;
526}
527
528bool ipc_rcu_getref(struct kern_ipc_perm *ptr)
529{
530 return refcount_inc_not_zero(&ptr->refcount);
531}
532
533void ipc_rcu_putref(struct kern_ipc_perm *ptr,
534 void (*func)(struct rcu_head *head))
535{
536 if (!refcount_dec_and_test(&ptr->refcount))
537 return;
538
539 call_rcu(&ptr->rcu, func);
540}
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552
553int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
554{
555 kuid_t euid = current_euid();
556 int requested_mode, granted_mode;
557
558 audit_ipc_obj(ipcp);
559 requested_mode = (flag >> 6) | (flag >> 3) | flag;
560 granted_mode = ipcp->mode;
561 if (uid_eq(euid, ipcp->cuid) ||
562 uid_eq(euid, ipcp->uid))
563 granted_mode >>= 6;
564 else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
565 granted_mode >>= 3;
566
567 if ((requested_mode & ~granted_mode & 0007) &&
568 !ns_capable(ns->user_ns, CAP_IPC_OWNER))
569 return -1;
570
571 return security_ipc_permission(ipcp, flag);
572}
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586
587void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
588{
589 out->key = in->key;
590 out->uid = from_kuid_munged(current_user_ns(), in->uid);
591 out->gid = from_kgid_munged(current_user_ns(), in->gid);
592 out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
593 out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
594 out->mode = in->mode;
595 out->seq = in->seq;
596}
597
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604
605
606void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
607{
608 out->key = in->key;
609 SET_UID(out->uid, in->uid);
610 SET_GID(out->gid, in->gid);
611 SET_UID(out->cuid, in->cuid);
612 SET_GID(out->cgid, in->cgid);
613 out->mode = in->mode;
614 out->seq = in->seq;
615}
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626
627struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id)
628{
629 struct kern_ipc_perm *out;
630 int idx = ipcid_to_idx(id);
631
632 out = idr_find(&ids->ipcs_idr, idx);
633 if (!out)
634 return ERR_PTR(-EINVAL);
635
636 return out;
637}
638
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647
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649
650struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
651{
652 struct kern_ipc_perm *out = ipc_obtain_object_idr(ids, id);
653
654 if (IS_ERR(out))
655 goto out;
656
657 if (ipc_checkid(out, id))
658 return ERR_PTR(-EINVAL);
659out:
660 return out;
661}
662
663
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669
670
671
672
673int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
674 const struct ipc_ops *ops, struct ipc_params *params)
675{
676 if (params->key == IPC_PRIVATE)
677 return ipcget_new(ns, ids, ops, params);
678 else
679 return ipcget_public(ns, ids, ops, params);
680}
681
682
683
684
685
686
687int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
688{
689 kuid_t uid = make_kuid(current_user_ns(), in->uid);
690 kgid_t gid = make_kgid(current_user_ns(), in->gid);
691 if (!uid_valid(uid) || !gid_valid(gid))
692 return -EINVAL;
693
694 out->uid = uid;
695 out->gid = gid;
696 out->mode = (out->mode & ~S_IRWXUGO)
697 | (in->mode & S_IRWXUGO);
698
699 return 0;
700}
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721
722struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns,
723 struct ipc_ids *ids, int id, int cmd,
724 struct ipc64_perm *perm, int extra_perm)
725{
726 kuid_t euid;
727 int err = -EPERM;
728 struct kern_ipc_perm *ipcp;
729
730 ipcp = ipc_obtain_object_check(ids, id);
731 if (IS_ERR(ipcp)) {
732 err = PTR_ERR(ipcp);
733 goto err;
734 }
735
736 audit_ipc_obj(ipcp);
737 if (cmd == IPC_SET)
738 audit_ipc_set_perm(extra_perm, perm->uid,
739 perm->gid, perm->mode);
740
741 euid = current_euid();
742 if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
743 ns_capable(ns->user_ns, CAP_SYS_ADMIN))
744 return ipcp;
745err:
746 return ERR_PTR(err);
747}
748
749#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
750
751
752
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754
755
756
757
758
759
760int ipc_parse_version(int *cmd)
761{
762 if (*cmd & IPC_64) {
763 *cmd ^= IPC_64;
764 return IPC_64;
765 } else {
766 return IPC_OLD;
767 }
768}
769
770#endif
771
772#ifdef CONFIG_PROC_FS
773struct ipc_proc_iter {
774 struct ipc_namespace *ns;
775 struct pid_namespace *pid_ns;
776 struct ipc_proc_iface *iface;
777};
778
779struct pid_namespace *ipc_seq_pid_ns(struct seq_file *s)
780{
781 struct ipc_proc_iter *iter = s->private;
782 return iter->pid_ns;
783}
784
785
786
787
788static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
789 loff_t *new_pos)
790{
791 struct kern_ipc_perm *ipc = NULL;
792 int max_idx = ipc_get_maxidx(ids);
793
794 if (max_idx == -1 || pos > max_idx)
795 goto out;
796
797 for (; pos <= max_idx; pos++) {
798 ipc = idr_find(&ids->ipcs_idr, pos);
799 if (ipc != NULL) {
800 rcu_read_lock();
801 ipc_lock_object(ipc);
802 break;
803 }
804 }
805out:
806 *new_pos = pos + 1;
807 return ipc;
808}
809
810static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
811{
812 struct ipc_proc_iter *iter = s->private;
813 struct ipc_proc_iface *iface = iter->iface;
814 struct kern_ipc_perm *ipc = it;
815
816
817 if (ipc && ipc != SEQ_START_TOKEN)
818 ipc_unlock(ipc);
819
820 return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
821}
822
823
824
825
826
827static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
828{
829 struct ipc_proc_iter *iter = s->private;
830 struct ipc_proc_iface *iface = iter->iface;
831 struct ipc_ids *ids;
832
833 ids = &iter->ns->ids[iface->ids];
834
835
836
837
838
839 down_read(&ids->rwsem);
840
841
842 if (*pos < 0)
843 return NULL;
844
845
846 if (*pos == 0)
847 return SEQ_START_TOKEN;
848
849
850 return sysvipc_find_ipc(ids, *pos - 1, pos);
851}
852
853static void sysvipc_proc_stop(struct seq_file *s, void *it)
854{
855 struct kern_ipc_perm *ipc = it;
856 struct ipc_proc_iter *iter = s->private;
857 struct ipc_proc_iface *iface = iter->iface;
858 struct ipc_ids *ids;
859
860
861 if (ipc && ipc != SEQ_START_TOKEN)
862 ipc_unlock(ipc);
863
864 ids = &iter->ns->ids[iface->ids];
865
866 up_read(&ids->rwsem);
867}
868
869static int sysvipc_proc_show(struct seq_file *s, void *it)
870{
871 struct ipc_proc_iter *iter = s->private;
872 struct ipc_proc_iface *iface = iter->iface;
873
874 if (it == SEQ_START_TOKEN) {
875 seq_puts(s, iface->header);
876 return 0;
877 }
878
879 return iface->show(s, it);
880}
881
882static const struct seq_operations sysvipc_proc_seqops = {
883 .start = sysvipc_proc_start,
884 .stop = sysvipc_proc_stop,
885 .next = sysvipc_proc_next,
886 .show = sysvipc_proc_show,
887};
888
889static int sysvipc_proc_open(struct inode *inode, struct file *file)
890{
891 struct ipc_proc_iter *iter;
892
893 iter = __seq_open_private(file, &sysvipc_proc_seqops, sizeof(*iter));
894 if (!iter)
895 return -ENOMEM;
896
897 iter->iface = pde_data(inode);
898 iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
899 iter->pid_ns = get_pid_ns(task_active_pid_ns(current));
900
901 return 0;
902}
903
904static int sysvipc_proc_release(struct inode *inode, struct file *file)
905{
906 struct seq_file *seq = file->private_data;
907 struct ipc_proc_iter *iter = seq->private;
908 put_ipc_ns(iter->ns);
909 put_pid_ns(iter->pid_ns);
910 return seq_release_private(inode, file);
911}
912
913static const struct proc_ops sysvipc_proc_ops = {
914 .proc_flags = PROC_ENTRY_PERMANENT,
915 .proc_open = sysvipc_proc_open,
916 .proc_read = seq_read,
917 .proc_lseek = seq_lseek,
918 .proc_release = sysvipc_proc_release,
919};
920#endif
921