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43#include <linux/mm.h>
44#include <linux/shm.h>
45#include <linux/init.h>
46#include <linux/msg.h>
47#include <linux/vmalloc.h>
48#include <linux/slab.h>
49#include <linux/notifier.h>
50#include <linux/capability.h>
51#include <linux/highuid.h>
52#include <linux/security.h>
53#include <linux/rcupdate.h>
54#include <linux/workqueue.h>
55#include <linux/seq_file.h>
56#include <linux/proc_fs.h>
57#include <linux/audit.h>
58#include <linux/nsproxy.h>
59#include <linux/rwsem.h>
60#include <linux/memory.h>
61#include <linux/ipc_namespace.h>
62
63#include <asm/unistd.h>
64
65#include "util.h"
66
67struct ipc_proc_iface {
68 const char *path;
69 const char *header;
70 int ids;
71 int (*show)(struct seq_file *, void *);
72};
73
74static void ipc_memory_notifier(struct work_struct *work)
75{
76 ipcns_notify(IPCNS_MEMCHANGED);
77}
78
79static int ipc_memory_callback(struct notifier_block *self,
80 unsigned long action, void *arg)
81{
82 static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
83
84 switch (action) {
85 case MEM_ONLINE:
86 case MEM_OFFLINE:
87
88
89
90
91
92
93
94 schedule_work(&ipc_memory_wq);
95 break;
96 case MEM_GOING_ONLINE:
97 case MEM_GOING_OFFLINE:
98 case MEM_CANCEL_ONLINE:
99 case MEM_CANCEL_OFFLINE:
100 default:
101 break;
102 }
103
104 return NOTIFY_OK;
105}
106
107static struct notifier_block ipc_memory_nb = {
108 .notifier_call = ipc_memory_callback,
109 .priority = IPC_CALLBACK_PRI,
110};
111
112
113
114
115
116
117
118
119
120
121
122static int __init ipc_init(void)
123{
124 sem_init();
125 msg_init();
126 shm_init();
127 register_hotmemory_notifier(&ipc_memory_nb);
128 register_ipcns_notifier(&init_ipc_ns);
129 return 0;
130}
131__initcall(ipc_init);
132
133
134
135
136
137
138
139
140void ipc_init_ids(struct ipc_ids *ids)
141{
142 ids->in_use = 0;
143 ids->seq = 0;
144 ids->next_id = -1;
145 init_rwsem(&ids->rwsem);
146 idr_init(&ids->ipcs_idr);
147}
148
149#ifdef CONFIG_PROC_FS
150static const struct file_operations sysvipc_proc_fops;
151
152
153
154
155
156
157
158void __init ipc_init_proc_interface(const char *path, const char *header,
159 int ids, int (*show)(struct seq_file *, void *))
160{
161 struct proc_dir_entry *pde;
162 struct ipc_proc_iface *iface;
163
164 iface = kmalloc(sizeof(*iface), GFP_KERNEL);
165 if (!iface)
166 return;
167 iface->path = path;
168 iface->header = header;
169 iface->ids = ids;
170 iface->show = show;
171
172 pde = proc_create_data(path,
173 S_IRUGO,
174 NULL,
175 &sysvipc_proc_fops,
176 iface);
177 if (!pde)
178 kfree(iface);
179}
180#endif
181
182
183
184
185
186
187
188
189
190
191
192static struct kern_ipc_perm *ipc_findkey(struct ipc_ids *ids, key_t key)
193{
194 struct kern_ipc_perm *ipc;
195 int next_id;
196 int total;
197
198 for (total = 0, next_id = 0; total < ids->in_use; next_id++) {
199 ipc = idr_find(&ids->ipcs_idr, next_id);
200
201 if (ipc == NULL)
202 continue;
203
204 if (ipc->key != key) {
205 total++;
206 continue;
207 }
208
209 rcu_read_lock();
210 ipc_lock_object(ipc);
211 return ipc;
212 }
213
214 return NULL;
215}
216
217
218
219
220
221
222
223int ipc_get_maxid(struct ipc_ids *ids)
224{
225 struct kern_ipc_perm *ipc;
226 int max_id = -1;
227 int total, id;
228
229 if (ids->in_use == 0)
230 return -1;
231
232 if (ids->in_use == IPCMNI)
233 return IPCMNI - 1;
234
235
236 total = 0;
237 for (id = 0; id < IPCMNI && total < ids->in_use; id++) {
238 ipc = idr_find(&ids->ipcs_idr, id);
239 if (ipc != NULL) {
240 max_id = id;
241 total++;
242 }
243 }
244 return max_id;
245}
246
247
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250
251
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255
256
257
258
259
260int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int size)
261{
262 kuid_t euid;
263 kgid_t egid;
264 int id;
265 int next_id = ids->next_id;
266
267 if (size > IPCMNI)
268 size = IPCMNI;
269
270 if (ids->in_use >= size)
271 return -ENOSPC;
272
273 idr_preload(GFP_KERNEL);
274
275 spin_lock_init(&new->lock);
276 new->deleted = false;
277 rcu_read_lock();
278 spin_lock(&new->lock);
279
280 id = idr_alloc(&ids->ipcs_idr, new,
281 (next_id < 0) ? 0 : ipcid_to_idx(next_id), 0,
282 GFP_NOWAIT);
283 idr_preload_end();
284 if (id < 0) {
285 spin_unlock(&new->lock);
286 rcu_read_unlock();
287 return id;
288 }
289
290 ids->in_use++;
291
292 current_euid_egid(&euid, &egid);
293 new->cuid = new->uid = euid;
294 new->gid = new->cgid = egid;
295
296 if (next_id < 0) {
297 new->seq = ids->seq++;
298 if (ids->seq > IPCID_SEQ_MAX)
299 ids->seq = 0;
300 } else {
301 new->seq = ipcid_to_seqx(next_id);
302 ids->next_id = -1;
303 }
304
305 new->id = ipc_buildid(id, new->seq);
306 return id;
307}
308
309
310
311
312
313
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315
316
317
318
319static int ipcget_new(struct ipc_namespace *ns, struct ipc_ids *ids,
320 struct ipc_ops *ops, struct ipc_params *params)
321{
322 int err;
323
324 down_write(&ids->rwsem);
325 err = ops->getnew(ns, params);
326 up_write(&ids->rwsem);
327 return err;
328}
329
330
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343
344
345static int ipc_check_perms(struct ipc_namespace *ns,
346 struct kern_ipc_perm *ipcp,
347 struct ipc_ops *ops,
348 struct ipc_params *params)
349{
350 int err;
351
352 if (ipcperms(ns, ipcp, params->flg))
353 err = -EACCES;
354 else {
355 err = ops->associate(ipcp, params->flg);
356 if (!err)
357 err = ipcp->id;
358 }
359
360 return err;
361}
362
363
364
365
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374
375
376
377static int ipcget_public(struct ipc_namespace *ns, struct ipc_ids *ids,
378 struct ipc_ops *ops, struct ipc_params *params)
379{
380 struct kern_ipc_perm *ipcp;
381 int flg = params->flg;
382 int err;
383
384
385
386
387
388 down_write(&ids->rwsem);
389 ipcp = ipc_findkey(ids, params->key);
390 if (ipcp == NULL) {
391
392 if (!(flg & IPC_CREAT))
393 err = -ENOENT;
394 else
395 err = ops->getnew(ns, params);
396 } else {
397
398
399 if (flg & IPC_CREAT && flg & IPC_EXCL)
400 err = -EEXIST;
401 else {
402 err = 0;
403 if (ops->more_checks)
404 err = ops->more_checks(ipcp, params);
405 if (!err)
406
407
408
409
410 err = ipc_check_perms(ns, ipcp, ops, params);
411 }
412 ipc_unlock(ipcp);
413 }
414 up_write(&ids->rwsem);
415
416 return err;
417}
418
419
420
421
422
423
424
425
426
427
428void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
429{
430 int lid = ipcid_to_idx(ipcp->id);
431
432 idr_remove(&ids->ipcs_idr, lid);
433 ids->in_use--;
434 ipcp->deleted = true;
435}
436
437
438
439
440
441
442
443
444void *ipc_alloc(int size)
445{
446 void *out;
447 if (size > PAGE_SIZE)
448 out = vmalloc(size);
449 else
450 out = kmalloc(size, GFP_KERNEL);
451 return out;
452}
453
454
455
456
457
458
459
460
461
462void ipc_free(void *ptr, int size)
463{
464 if (size > PAGE_SIZE)
465 vfree(ptr);
466 else
467 kfree(ptr);
468}
469
470
471
472
473
474
475
476
477void *ipc_rcu_alloc(int size)
478{
479
480
481
482 struct ipc_rcu *out = ipc_alloc(sizeof(struct ipc_rcu) + size);
483 if (unlikely(!out))
484 return NULL;
485 atomic_set(&out->refcount, 1);
486 return out + 1;
487}
488
489int ipc_rcu_getref(void *ptr)
490{
491 struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
492
493 return atomic_inc_not_zero(&p->refcount);
494}
495
496void ipc_rcu_putref(void *ptr, void (*func)(struct rcu_head *head))
497{
498 struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1;
499
500 if (!atomic_dec_and_test(&p->refcount))
501 return;
502
503 call_rcu(&p->rcu, func);
504}
505
506void ipc_rcu_free(struct rcu_head *head)
507{
508 struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
509
510 if (is_vmalloc_addr(p))
511 vfree(p);
512 else
513 kfree(p);
514}
515
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518
519
520
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525
526
527int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
528{
529 kuid_t euid = current_euid();
530 int requested_mode, granted_mode;
531
532 audit_ipc_obj(ipcp);
533 requested_mode = (flag >> 6) | (flag >> 3) | flag;
534 granted_mode = ipcp->mode;
535 if (uid_eq(euid, ipcp->cuid) ||
536 uid_eq(euid, ipcp->uid))
537 granted_mode >>= 6;
538 else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
539 granted_mode >>= 3;
540
541 if ((requested_mode & ~granted_mode & 0007) &&
542 !ns_capable(ns->user_ns, CAP_IPC_OWNER))
543 return -1;
544
545 return security_ipc_permission(ipcp, flag);
546}
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559
560
561void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out)
562{
563 out->key = in->key;
564 out->uid = from_kuid_munged(current_user_ns(), in->uid);
565 out->gid = from_kgid_munged(current_user_ns(), in->gid);
566 out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
567 out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
568 out->mode = in->mode;
569 out->seq = in->seq;
570}
571
572
573
574
575
576
577
578
579
580void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out)
581{
582 out->key = in->key;
583 SET_UID(out->uid, in->uid);
584 SET_GID(out->gid, in->gid);
585 SET_UID(out->cuid, in->cuid);
586 SET_GID(out->cgid, in->cgid);
587 out->mode = in->mode;
588 out->seq = in->seq;
589}
590
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593
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596
597
598
599
600
601struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id)
602{
603 struct kern_ipc_perm *out;
604 int lid = ipcid_to_idx(id);
605
606 out = idr_find(&ids->ipcs_idr, lid);
607 if (!out)
608 return ERR_PTR(-EINVAL);
609
610 return out;
611}
612
613
614
615
616
617
618
619
620
621
622struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
623{
624 struct kern_ipc_perm *out;
625
626 rcu_read_lock();
627 out = ipc_obtain_object(ids, id);
628 if (IS_ERR(out))
629 goto err1;
630
631 spin_lock(&out->lock);
632
633
634
635
636 if (ipc_valid_object(out))
637 return out;
638
639 spin_unlock(&out->lock);
640 out = ERR_PTR(-EINVAL);
641err1:
642 rcu_read_unlock();
643 return out;
644}
645
646
647
648
649
650
651
652
653
654
655
656
657struct kern_ipc_perm *ipc_obtain_object_check(struct ipc_ids *ids, int id)
658{
659 struct kern_ipc_perm *out = ipc_obtain_object(ids, id);
660
661 if (IS_ERR(out))
662 goto out;
663
664 if (ipc_checkid(out, id))
665 return ERR_PTR(-EIDRM);
666out:
667 return out;
668}
669
670
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672
673
674
675
676
677
678
679
680int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
681 struct ipc_ops *ops, struct ipc_params *params)
682{
683 if (params->key == IPC_PRIVATE)
684 return ipcget_new(ns, ids, ops, params);
685 else
686 return ipcget_public(ns, ids, ops, params);
687}
688
689
690
691
692
693
694int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
695{
696 kuid_t uid = make_kuid(current_user_ns(), in->uid);
697 kgid_t gid = make_kgid(current_user_ns(), in->gid);
698 if (!uid_valid(uid) || !gid_valid(gid))
699 return -EINVAL;
700
701 out->uid = uid;
702 out->gid = gid;
703 out->mode = (out->mode & ~S_IRWXUGO)
704 | (in->mode & S_IRWXUGO);
705
706 return 0;
707}
708
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715
716
717
718
719
720
721
722
723
724
725
726
727struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,
728 struct ipc_ids *ids, int id, int cmd,
729 struct ipc64_perm *perm, int extra_perm)
730{
731 kuid_t euid;
732 int err = -EPERM;
733 struct kern_ipc_perm *ipcp;
734
735 ipcp = ipc_obtain_object_check(ids, id);
736 if (IS_ERR(ipcp)) {
737 err = PTR_ERR(ipcp);
738 goto err;
739 }
740
741 audit_ipc_obj(ipcp);
742 if (cmd == IPC_SET)
743 audit_ipc_set_perm(extra_perm, perm->uid,
744 perm->gid, perm->mode);
745
746 euid = current_euid();
747 if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
748 ns_capable(ns->user_ns, CAP_SYS_ADMIN))
749 return ipcp;
750err:
751 return ERR_PTR(err);
752}
753
754#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
755
756
757
758
759
760
761
762
763
764
765int ipc_parse_version(int *cmd)
766{
767 if (*cmd & IPC_64) {
768 *cmd ^= IPC_64;
769 return IPC_64;
770 } else {
771 return IPC_OLD;
772 }
773}
774
775#endif
776
777#ifdef CONFIG_PROC_FS
778struct ipc_proc_iter {
779 struct ipc_namespace *ns;
780 struct ipc_proc_iface *iface;
781};
782
783
784
785
786static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
787 loff_t *new_pos)
788{
789 struct kern_ipc_perm *ipc;
790 int total, id;
791
792 total = 0;
793 for (id = 0; id < pos && total < ids->in_use; id++) {
794 ipc = idr_find(&ids->ipcs_idr, id);
795 if (ipc != NULL)
796 total++;
797 }
798
799 if (total >= ids->in_use)
800 return NULL;
801
802 for (; pos < IPCMNI; pos++) {
803 ipc = idr_find(&ids->ipcs_idr, pos);
804 if (ipc != NULL) {
805 *new_pos = pos + 1;
806 rcu_read_lock();
807 ipc_lock_object(ipc);
808 return ipc;
809 }
810 }
811
812
813 return NULL;
814}
815
816static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)
817{
818 struct ipc_proc_iter *iter = s->private;
819 struct ipc_proc_iface *iface = iter->iface;
820 struct kern_ipc_perm *ipc = it;
821
822
823 if (ipc && ipc != SEQ_START_TOKEN)
824 ipc_unlock(ipc);
825
826 return sysvipc_find_ipc(&iter->ns->ids[iface->ids], *pos, pos);
827}
828
829
830
831
832
833static void *sysvipc_proc_start(struct seq_file *s, loff_t *pos)
834{
835 struct ipc_proc_iter *iter = s->private;
836 struct ipc_proc_iface *iface = iter->iface;
837 struct ipc_ids *ids;
838
839 ids = &iter->ns->ids[iface->ids];
840
841
842
843
844
845 down_read(&ids->rwsem);
846
847
848 if (*pos < 0)
849 return NULL;
850
851
852 if (*pos == 0)
853 return SEQ_START_TOKEN;
854
855
856 return sysvipc_find_ipc(ids, *pos - 1, pos);
857}
858
859static void sysvipc_proc_stop(struct seq_file *s, void *it)
860{
861 struct kern_ipc_perm *ipc = it;
862 struct ipc_proc_iter *iter = s->private;
863 struct ipc_proc_iface *iface = iter->iface;
864 struct ipc_ids *ids;
865
866
867 if (ipc && ipc != SEQ_START_TOKEN)
868 ipc_unlock(ipc);
869
870 ids = &iter->ns->ids[iface->ids];
871
872 up_read(&ids->rwsem);
873}
874
875static int sysvipc_proc_show(struct seq_file *s, void *it)
876{
877 struct ipc_proc_iter *iter = s->private;
878 struct ipc_proc_iface *iface = iter->iface;
879
880 if (it == SEQ_START_TOKEN)
881 return seq_puts(s, iface->header);
882
883 return iface->show(s, it);
884}
885
886static const struct seq_operations sysvipc_proc_seqops = {
887 .start = sysvipc_proc_start,
888 .stop = sysvipc_proc_stop,
889 .next = sysvipc_proc_next,
890 .show = sysvipc_proc_show,
891};
892
893static int sysvipc_proc_open(struct inode *inode, struct file *file)
894{
895 int ret;
896 struct seq_file *seq;
897 struct ipc_proc_iter *iter;
898
899 ret = -ENOMEM;
900 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
901 if (!iter)
902 goto out;
903
904 ret = seq_open(file, &sysvipc_proc_seqops);
905 if (ret) {
906 kfree(iter);
907 goto out;
908 }
909
910 seq = file->private_data;
911 seq->private = iter;
912
913 iter->iface = PDE_DATA(inode);
914 iter->ns = get_ipc_ns(current->nsproxy->ipc_ns);
915out:
916 return ret;
917}
918
919static int sysvipc_proc_release(struct inode *inode, struct file *file)
920{
921 struct seq_file *seq = file->private_data;
922 struct ipc_proc_iter *iter = seq->private;
923 put_ipc_ns(iter->ns);
924 return seq_release_private(inode, file);
925}
926
927static const struct file_operations sysvipc_proc_fops = {
928 .open = sysvipc_proc_open,
929 .read = seq_read,
930 .llseek = seq_lseek,
931 .release = sysvipc_proc_release,
932};
933#endif
934