1 // SPDX-License-Identifier: GPL-2.0 1
2 /*
3 * linux/kernel/seccomp.c
4 *
5 * Copyright 2004-2005 Andrea Arcangeli <andr
6 *
7 * Copyright (C) 2012 Google, Inc.
8 * Will Drewry <wad@chromium.org>
9 *
10 * This defines a simple but solid secure-comp
11 *
12 * Mode 1 uses a fixed list of allowed system
13 * Mode 2 allows user-defined system call filt
14 * of Berkeley Packet Filters/Linux Soc
15 */
16 #define pr_fmt(fmt) "seccomp: " fmt
17
18 #include <linux/refcount.h>
19 #include <linux/audit.h>
20 #include <linux/compat.h>
21 #include <linux/coredump.h>
22 #include <linux/kmemleak.h>
23 #include <linux/nospec.h>
24 #include <linux/prctl.h>
25 #include <linux/sched.h>
26 #include <linux/sched/task_stack.h>
27 #include <linux/seccomp.h>
28 #include <linux/slab.h>
29 #include <linux/syscalls.h>
30 #include <linux/sysctl.h>
31
32 /* Not exposed in headers: strictly internal u
33 #define SECCOMP_MODE_DEAD (SECCOMP_MODE_
34
35 #ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
36 #include <asm/syscall.h>
37 #endif
38
39 #ifdef CONFIG_SECCOMP_FILTER
40 #include <linux/file.h>
41 #include <linux/filter.h>
42 #include <linux/pid.h>
43 #include <linux/ptrace.h>
44 #include <linux/capability.h>
45 #include <linux/uaccess.h>
46 #include <linux/anon_inodes.h>
47 #include <linux/lockdep.h>
48
49 /*
50 * When SECCOMP_IOCTL_NOTIF_ID_VALID was first
51 * wrong direction flag in the ioctl number. T
52 * which the kernel needs to keep supporting u
53 * using the wrong command number.
54 */
55 #define SECCOMP_IOCTL_NOTIF_ID_VALID_WRONG_DIR
56
57 enum notify_state {
58 SECCOMP_NOTIFY_INIT,
59 SECCOMP_NOTIFY_SENT,
60 SECCOMP_NOTIFY_REPLIED,
61 };
62
63 struct seccomp_knotif {
64 /* The struct pid of the task whose fi
65 struct task_struct *task;
66
67 /* The "cookie" for this request; this
68 u64 id;
69
70 /*
71 * The seccomp data. This pointer is v
72 * notification is active, since it co
73 * eclipses the entire lifecycle here.
74 */
75 const struct seccomp_data *data;
76
77 /*
78 * Notification states. When SECCOMP_R
79 * struct seccomp_knotif is created an
80 * handler reads the notification off
81 * If a signal is received the state t
82 * another message is sent. When the u
83 * transitions to REPLIED.
84 */
85 enum notify_state state;
86
87 /* The return values, only valid when
88 int error;
89 long val;
90 u32 flags;
91
92 /*
93 * Signals when this has changed state
94 * dying, a new seccomp addfd message,
95 */
96 struct completion ready;
97
98 struct list_head list;
99
100 /* outstanding addfd requests */
101 struct list_head addfd;
102 };
103
104 /**
105 * struct seccomp_kaddfd - container for secco
106 *
107 * @file: A reference to the file to install i
108 * @fd: The fd number to install it at. If the
109 * installing process should allocate the
110 * @flags: The flags for the new file descript
111 * is allowed.
112 * @ioctl_flags: The flags used for the seccom
113 * @setfd: whether or not SECCOMP_ADDFD_FLAG_S
114 * @ret: The return value of the installing pr
115 * upon success (>= 0).
116 * @completion: Indicates that the installing
117 * installation, or gone away (ei
118 * reply, or signal)
119 * @list: list_head for chaining seccomp_kaddf
120 *
121 */
122 struct seccomp_kaddfd {
123 struct file *file;
124 int fd;
125 unsigned int flags;
126 __u32 ioctl_flags;
127
128 union {
129 bool setfd;
130 /* To only be set on reply */
131 int ret;
132 };
133 struct completion completion;
134 struct list_head list;
135 };
136
137 /**
138 * struct notification - container for seccomp
139 * most seccomp filters will not have notifica
140 * structure is fairly large, we store the not
141 * separate structure.
142 *
143 * @requests: A semaphore that users of this n
144 * changes. Actual reads and writes
145 * filter->notify_lock.
146 * @flags: A set of SECCOMP_USER_NOTIF_FD_* fl
147 * @next_id: The id of the next request.
148 * @notifications: A list of struct seccomp_kn
149 */
150
151 struct notification {
152 atomic_t requests;
153 u32 flags;
154 u64 next_id;
155 struct list_head notifications;
156 };
157
158 #ifdef SECCOMP_ARCH_NATIVE
159 /**
160 * struct action_cache - per-filter cache of s
161 * arch/syscall pair
162 *
163 * @allow_native: A bitmap where each bit repr
164 * filter will always allow the
165 * native architecture.
166 * @allow_compat: A bitmap where each bit repr
167 * filter will always allow the
168 * compat architecture.
169 */
170 struct action_cache {
171 DECLARE_BITMAP(allow_native, SECCOMP_A
172 #ifdef SECCOMP_ARCH_COMPAT
173 DECLARE_BITMAP(allow_compat, SECCOMP_A
174 #endif
175 };
176 #else
177 struct action_cache { };
178
179 static inline bool seccomp_cache_check_allow(c
180 c
181 {
182 return false;
183 }
184
185 static inline void seccomp_cache_prepare(struc
186 {
187 }
188 #endif /* SECCOMP_ARCH_NATIVE */
189
190 /**
191 * struct seccomp_filter - container for secco
192 *
193 * @refs: Reference count to manage the object
194 * A filter's reference count is increm
195 * attached task, once for the dependen
196 * requested for the user notifier. Whe
197 * the filter can be freed.
198 * @users: A filter's @users count is incremen
199 * attached task (filter installation,
200 * and once for the dependent filter (
201 * When it reaches zero it indicates t
202 * users of that filter exist. No new
203 * this filter after reaching 0. The @
204 * or equal to @refs. Hence, reaching
205 * the filter can be freed.
206 * @cache: cache of arch/syscall mappings to a
207 * @log: true if all actions except for SECCOM
208 * @wait_killable_recv: Put notifying process
209 * notification is receiv
210 * @prev: points to a previously installed, or
211 * @prog: the BPF program to evaluate
212 * @notif: the struct that holds all notificat
213 * @notify_lock: A lock for all notification-r
214 * @wqh: A wait queue for poll if a notifier i
215 *
216 * seccomp_filter objects are organized in a t
217 * pointer. For any task, it appears to be a
218 * with current->seccomp.filter, the most rece
219 * However, multiple filters may share a @prev
220 * results in a unidirectional tree existing i
221 * how namespaces work.
222 *
223 * seccomp_filter objects should never be modi
224 * to a task_struct (other than @refs).
225 */
226 struct seccomp_filter {
227 refcount_t refs;
228 refcount_t users;
229 bool log;
230 bool wait_killable_recv;
231 struct action_cache cache;
232 struct seccomp_filter *prev;
233 struct bpf_prog *prog;
234 struct notification *notif;
235 struct mutex notify_lock;
236 wait_queue_head_t wqh;
237 };
238
239 /* Limit any path through the tree to 256KB wo
240 #define MAX_INSNS_PER_PATH ((1 << 18) / sizeof
241
242 /*
243 * Endianness is explicitly ignored and left f
244 * as per the specific architecture.
245 */
246 static void populate_seccomp_data(struct secco
247 {
248 /*
249 * Instead of using current_pt_reg(),
250 * to safely fetch "current", so just
251 */
252 struct task_struct *task = current;
253 struct pt_regs *regs = task_pt_regs(ta
254 unsigned long args[6];
255
256 sd->nr = syscall_get_nr(task, regs);
257 sd->arch = syscall_get_arch(task);
258 syscall_get_arguments(task, regs, args
259 sd->args[0] = args[0];
260 sd->args[1] = args[1];
261 sd->args[2] = args[2];
262 sd->args[3] = args[3];
263 sd->args[4] = args[4];
264 sd->args[5] = args[5];
265 sd->instruction_pointer = KSTK_EIP(tas
266 }
267
268 /**
269 * seccomp_check_filter - verify seccomp
270 * @filter: filter to verify
271 * @flen: length of filter
272 *
273 * Takes a previously checked filter (by bpf_c
274 * redirects all filter code that loads struct
275 * and related data through seccomp_bpf_load.
276 * enforces length and alignment checking of t
277 *
278 * Returns 0 if the rule set is legal or -EINV
279 */
280 static int seccomp_check_filter(struct sock_fi
281 {
282 int pc;
283 for (pc = 0; pc < flen; pc++) {
284 struct sock_filter *ftest = &f
285 u16 code = ftest->code;
286 u32 k = ftest->k;
287
288 switch (code) {
289 case BPF_LD | BPF_W | BPF_ABS:
290 ftest->code = BPF_LDX
291 /* 32-bit aligned and
292 if (k >= sizeof(struct
293 return -EINVAL
294 continue;
295 case BPF_LD | BPF_W | BPF_LEN:
296 ftest->code = BPF_LD |
297 ftest->k = sizeof(stru
298 continue;
299 case BPF_LDX | BPF_W | BPF_LEN
300 ftest->code = BPF_LDX
301 ftest->k = sizeof(stru
302 continue;
303 /* Explicitly include allowed
304 case BPF_RET | BPF_K:
305 case BPF_RET | BPF_A:
306 case BPF_ALU | BPF_ADD | BPF_K
307 case BPF_ALU | BPF_ADD | BPF_X
308 case BPF_ALU | BPF_SUB | BPF_K
309 case BPF_ALU | BPF_SUB | BPF_X
310 case BPF_ALU | BPF_MUL | BPF_K
311 case BPF_ALU | BPF_MUL | BPF_X
312 case BPF_ALU | BPF_DIV | BPF_K
313 case BPF_ALU | BPF_DIV | BPF_X
314 case BPF_ALU | BPF_AND | BPF_K
315 case BPF_ALU | BPF_AND | BPF_X
316 case BPF_ALU | BPF_OR | BPF_K:
317 case BPF_ALU | BPF_OR | BPF_X:
318 case BPF_ALU | BPF_XOR | BPF_K
319 case BPF_ALU | BPF_XOR | BPF_X
320 case BPF_ALU | BPF_LSH | BPF_K
321 case BPF_ALU | BPF_LSH | BPF_X
322 case BPF_ALU | BPF_RSH | BPF_K
323 case BPF_ALU | BPF_RSH | BPF_X
324 case BPF_ALU | BPF_NEG:
325 case BPF_LD | BPF_IMM:
326 case BPF_LDX | BPF_IMM:
327 case BPF_MISC | BPF_TAX:
328 case BPF_MISC | BPF_TXA:
329 case BPF_LD | BPF_MEM:
330 case BPF_LDX | BPF_MEM:
331 case BPF_ST:
332 case BPF_STX:
333 case BPF_JMP | BPF_JA:
334 case BPF_JMP | BPF_JEQ | BPF_K
335 case BPF_JMP | BPF_JEQ | BPF_X
336 case BPF_JMP | BPF_JGE | BPF_K
337 case BPF_JMP | BPF_JGE | BPF_X
338 case BPF_JMP | BPF_JGT | BPF_K
339 case BPF_JMP | BPF_JGT | BPF_X
340 case BPF_JMP | BPF_JSET | BPF_
341 case BPF_JMP | BPF_JSET | BPF_
342 continue;
343 default:
344 return -EINVAL;
345 }
346 }
347 return 0;
348 }
349
350 #ifdef SECCOMP_ARCH_NATIVE
351 static inline bool seccomp_cache_check_allow_b
352
353
354 {
355 if (unlikely(syscall_nr < 0 || syscall
356 return false;
357 syscall_nr = array_index_nospec(syscal
358
359 return test_bit(syscall_nr, bitmap);
360 }
361
362 /**
363 * seccomp_cache_check_allow - lookup seccomp
364 * @sfilter: The seccomp filter
365 * @sd: The seccomp data to lookup the cache w
366 *
367 * Returns true if the seccomp_data is cached
368 */
369 static inline bool seccomp_cache_check_allow(c
370 c
371 {
372 int syscall_nr = sd->nr;
373 const struct action_cache *cache = &sf
374
375 #ifndef SECCOMP_ARCH_COMPAT
376 /* A native-only architecture doesn't
377 return seccomp_cache_check_allow_bitma
378
379
380 #else
381 if (likely(sd->arch == SECCOMP_ARCH_NA
382 return seccomp_cache_check_all
383
384
385 if (likely(sd->arch == SECCOMP_ARCH_CO
386 return seccomp_cache_check_all
387
388
389 #endif /* SECCOMP_ARCH_COMPAT */
390
391 WARN_ON_ONCE(true);
392 return false;
393 }
394 #endif /* SECCOMP_ARCH_NATIVE */
395
396 #define ACTION_ONLY(ret) ((s32)((ret) & (SECCO
397 /**
398 * seccomp_run_filters - evaluates all seccomp
399 * @sd: optional seccomp data to be passed to
400 * @match: stores struct seccomp_filter that r
401 * unless filter returned SECCOMP_RET_
402 * be unchanged.
403 *
404 * Returns valid seccomp BPF response codes.
405 */
406 static u32 seccomp_run_filters(const struct se
407 struct seccomp_
408 {
409 u32 ret = SECCOMP_RET_ALLOW;
410 /* Make sure cross-thread synced filte
411 struct seccomp_filter *f =
412 READ_ONCE(current->sec
413
414 /* Ensure unexpected behavior doesn't
415 if (WARN_ON(f == NULL))
416 return SECCOMP_RET_KILL_PROCES
417
418 if (seccomp_cache_check_allow(f, sd))
419 return SECCOMP_RET_ALLOW;
420
421 /*
422 * All filters in the list are evaluat
423 * value always takes priority (ignori
424 */
425 for (; f; f = f->prev) {
426 u32 cur_ret = bpf_prog_run_pin
427
428 if (ACTION_ONLY(cur_ret) < ACT
429 ret = cur_ret;
430 *match = f;
431 }
432 }
433 return ret;
434 }
435 #endif /* CONFIG_SECCOMP_FILTER */
436
437 static inline bool seccomp_may_assign_mode(uns
438 {
439 assert_spin_locked(¤t->sighand->
440
441 if (current->seccomp.mode && current->
442 return false;
443
444 return true;
445 }
446
447 void __weak arch_seccomp_spec_mitigate(struct
448
449 static inline void seccomp_assign_mode(struct
450 unsigne
451 unsigne
452 {
453 assert_spin_locked(&task->sighand->sig
454
455 task->seccomp.mode = seccomp_mode;
456 /*
457 * Make sure SYSCALL_WORK_SECCOMP cann
458 * filter) is set.
459 */
460 smp_mb__before_atomic();
461 /* Assume default seccomp processes wa
462 if ((flags & SECCOMP_FILTER_FLAG_SPEC_
463 arch_seccomp_spec_mitigate(tas
464 set_task_syscall_work(task, SECCOMP);
465 }
466
467 #ifdef CONFIG_SECCOMP_FILTER
468 /* Returns 1 if the parent is an ancestor of t
469 static int is_ancestor(struct seccomp_filter *
470 struct seccomp_filter *
471 {
472 /* NULL is the root ancestor. */
473 if (parent == NULL)
474 return 1;
475 for (; child; child = child->prev)
476 if (child == parent)
477 return 1;
478 return 0;
479 }
480
481 /**
482 * seccomp_can_sync_threads: checks if all thr
483 *
484 * Expects sighand and cred_guard_mutex locks
485 *
486 * Returns 0 on success, -ve on error, or the
487 * either not in the correct seccomp mode or d
488 * seccomp filter.
489 */
490 static inline pid_t seccomp_can_sync_threads(v
491 {
492 struct task_struct *thread, *caller;
493
494 BUG_ON(!mutex_is_locked(¤t->sign
495 assert_spin_locked(¤t->sighand->
496
497 /* Validate all threads being eligible
498 caller = current;
499 for_each_thread(caller, thread) {
500 pid_t failed;
501
502 /* Skip current, since it is i
503 if (thread == caller)
504 continue;
505 /* Skip exited threads. */
506 if (thread->flags & PF_EXITING
507 continue;
508
509 if (thread->seccomp.mode == SE
510 (thread->seccomp.mode == S
511 is_ancestor(thread->secco
512 caller->secco
513 continue;
514
515 /* Return the first thread tha
516 failed = task_pid_vnr(thread);
517 /* If the pid cannot be resolv
518 if (WARN_ON(failed == 0))
519 failed = -ESRCH;
520 return failed;
521 }
522
523 return 0;
524 }
525
526 static inline void seccomp_filter_free(struct
527 {
528 if (filter) {
529 bpf_prog_destroy(filter->prog)
530 kfree(filter);
531 }
532 }
533
534 static void __seccomp_filter_orphan(struct sec
535 {
536 while (orig && refcount_dec_and_test(&
537 if (waitqueue_active(&orig->wq
538 wake_up_poll(&orig->wq
539 orig = orig->prev;
540 }
541 }
542
543 static void __put_seccomp_filter(struct seccom
544 {
545 /* Clean up single-reference branches
546 while (orig && refcount_dec_and_test(&
547 struct seccomp_filter *freeme
548 orig = orig->prev;
549 seccomp_filter_free(freeme);
550 }
551 }
552
553 static void __seccomp_filter_release(struct se
554 {
555 /* Notify about any unused filters in
556 __seccomp_filter_orphan(orig);
557 /* Finally drop all references to the
558 __put_seccomp_filter(orig);
559 }
560
561 /**
562 * seccomp_filter_release - Detach the task fr
563 * drop its reference
564 * about unused filte
565 *
566 * @tsk: task the filter should be released fr
567 *
568 * This function should only be called when th
569 * it detaches it from its filter tree. PF_EXI
570 * for the task.
571 */
572 void seccomp_filter_release(struct task_struct
573 {
574 struct seccomp_filter *orig;
575
576 if (WARN_ON((tsk->flags & PF_EXITING)
577 return;
578
579 spin_lock_irq(&tsk->sighand->siglock);
580 orig = tsk->seccomp.filter;
581 /* Detach task from its filter tree. *
582 tsk->seccomp.filter = NULL;
583 spin_unlock_irq(&tsk->sighand->siglock
584 __seccomp_filter_release(orig);
585 }
586
587 /**
588 * seccomp_sync_threads: sets all threads to u
589 *
590 * @flags: SECCOMP_FILTER_FLAG_* flags to set
591 *
592 * Expects sighand and cred_guard_mutex locks
593 * seccomp_can_sync_threads() to have returned
594 * without dropping the locks.
595 *
596 */
597 static inline void seccomp_sync_threads(unsign
598 {
599 struct task_struct *thread, *caller;
600
601 BUG_ON(!mutex_is_locked(¤t->sign
602 assert_spin_locked(¤t->sighand->
603
604 /* Synchronize all threads. */
605 caller = current;
606 for_each_thread(caller, thread) {
607 /* Skip current, since it need
608 if (thread == caller)
609 continue;
610
611 /*
612 * Skip exited threads. seccom
613 * been already called for thi
614 */
615 if (thread->flags & PF_EXITING
616 continue;
617
618 /* Get a task reference for th
619 get_seccomp_filter(caller);
620
621 /*
622 * Drop the task reference to
623 * current's path will hold a
624 * allows a put before the ass
625 */
626 __seccomp_filter_release(threa
627
628 /* Make our new filter tree vi
629 smp_store_release(&thread->sec
630 caller->secc
631 atomic_set(&thread->seccomp.fi
632 atomic_read(&caller
633
634 /*
635 * Don't let an unprivileged t
636 * the no_new_privs restrictio
637 * a thread that sets it up, e
638 * then dies.
639 */
640 if (task_no_new_privs(caller))
641 task_set_no_new_privs(
642
643 /*
644 * Opt the other thread into s
645 * As threads are considered t
646 * equivalent (see ptrace_may_
647 * allow one thread to transit
648 */
649 if (thread->seccomp.mode == SE
650 seccomp_assign_mode(th
651 fl
652 }
653 }
654
655 /**
656 * seccomp_prepare_filter: Prepares a seccomp
657 * @fprog: BPF program to install
658 *
659 * Returns filter on success or an ERR_PTR on
660 */
661 static struct seccomp_filter *seccomp_prepare_
662 {
663 struct seccomp_filter *sfilter;
664 int ret;
665 const bool save_orig =
666 #if defined(CONFIG_CHECKPOINT_RESTORE) || defi
667 true;
668 #else
669 false;
670 #endif
671
672 if (fprog->len == 0 || fprog->len > BP
673 return ERR_PTR(-EINVAL);
674
675 BUG_ON(INT_MAX / fprog->len < sizeof(s
676
677 /*
678 * Installing a seccomp filter require
679 * CAP_SYS_ADMIN in its namespace or b
680 * This avoids scenarios where unprivi
681 * behavior of privileged children.
682 */
683 if (!task_no_new_privs(current) &&
684 !ns_capable_noaudit(cu
685 return ERR_PTR(-EACCES);
686
687 /* Allocate a new seccomp_filter */
688 sfilter = kzalloc(sizeof(*sfilter), GF
689 if (!sfilter)
690 return ERR_PTR(-ENOMEM);
691
692 mutex_init(&sfilter->notify_lock);
693 ret = bpf_prog_create_from_user(&sfilt
694 seccom
695 if (ret < 0) {
696 kfree(sfilter);
697 return ERR_PTR(ret);
698 }
699
700 refcount_set(&sfilter->refs, 1);
701 refcount_set(&sfilter->users, 1);
702 init_waitqueue_head(&sfilter->wqh);
703
704 return sfilter;
705 }
706
707 /**
708 * seccomp_prepare_user_filter - prepares a us
709 * @user_filter: pointer to the user data cont
710 *
711 * Returns 0 on success and non-zero otherwise
712 */
713 static struct seccomp_filter *
714 seccomp_prepare_user_filter(const char __user
715 {
716 struct sock_fprog fprog;
717 struct seccomp_filter *filter = ERR_PT
718
719 #ifdef CONFIG_COMPAT
720 if (in_compat_syscall()) {
721 struct compat_sock_fprog fprog
722 if (copy_from_user(&fprog32, u
723 goto out;
724 fprog.len = fprog32.len;
725 fprog.filter = compat_ptr(fpro
726 } else /* falls through to the if belo
727 #endif
728 if (copy_from_user(&fprog, user_filter
729 goto out;
730 filter = seccomp_prepare_filter(&fprog
731 out:
732 return filter;
733 }
734
735 #ifdef SECCOMP_ARCH_NATIVE
736 /**
737 * seccomp_is_const_allow - check if filter is
738 * @fprog: The BPF programs
739 * @sd: The seccomp data to check against, onl
740 * number are considered constant.
741 */
742 static bool seccomp_is_const_allow(struct sock
743 struct secc
744 {
745 unsigned int reg_value = 0;
746 unsigned int pc;
747 bool op_res;
748
749 if (WARN_ON_ONCE(!fprog))
750 return false;
751
752 for (pc = 0; pc < fprog->len; pc++) {
753 struct sock_filter *insn = &fp
754 u16 code = insn->code;
755 u32 k = insn->k;
756
757 switch (code) {
758 case BPF_LD | BPF_W | BPF_ABS:
759 switch (k) {
760 case offsetof(struct s
761 reg_value = sd
762 break;
763 case offsetof(struct s
764 reg_value = sd
765 break;
766 default:
767 /* can't optim
768 return false;
769 }
770 break;
771 case BPF_RET | BPF_K:
772 /* reached return with
773 return k == SECCOMP_RE
774 case BPF_JMP | BPF_JA:
775 pc += insn->k;
776 break;
777 case BPF_JMP | BPF_JEQ | BPF_K
778 case BPF_JMP | BPF_JGE | BPF_K
779 case BPF_JMP | BPF_JGT | BPF_K
780 case BPF_JMP | BPF_JSET | BPF_
781 switch (BPF_OP(code))
782 case BPF_JEQ:
783 op_res = reg_v
784 break;
785 case BPF_JGE:
786 op_res = reg_v
787 break;
788 case BPF_JGT:
789 op_res = reg_v
790 break;
791 case BPF_JSET:
792 op_res = !!(re
793 break;
794 default:
795 /* can't optim
796 return false;
797 }
798
799 pc += op_res ? insn->j
800 break;
801 case BPF_ALU | BPF_AND | BPF_K
802 reg_value &= k;
803 break;
804 default:
805 /* can't optimize (unk
806 return false;
807 }
808 }
809
810 /* ran off the end of the filter?! */
811 WARN_ON(1);
812 return false;
813 }
814
815 static void seccomp_cache_prepare_bitmap(struc
816 void
817 size_
818 {
819 struct sock_fprog_kern *fprog = sfilte
820 struct seccomp_data sd;
821 int nr;
822
823 if (bitmap_prev) {
824 /* The new filter must be as r
825 bitmap_copy(bitmap, bitmap_pre
826 } else {
827 /* Before any filters, all sys
828 bitmap_fill(bitmap, bitmap_siz
829 }
830
831 for (nr = 0; nr < bitmap_size; nr++) {
832 /* No bitmap change: not a cac
833 if (!test_bit(nr, bitmap))
834 continue;
835
836 sd.nr = nr;
837 sd.arch = arch;
838
839 /* No bitmap change: continue
840 if (seccomp_is_const_allow(fpr
841 continue;
842
843 /*
844 * Not a cacheable action: alw
845 * atomic clear_bit() not need
846 */
847 __clear_bit(nr, bitmap);
848 }
849 }
850
851 /**
852 * seccomp_cache_prepare - emulate the filter
853 * @sfilter: The seccomp filter
854 *
855 * Returns 0 if successful or -errno if error
856 */
857 static void seccomp_cache_prepare(struct secco
858 {
859 struct action_cache *cache = &sfilter-
860 const struct action_cache *cache_prev
861 sfilter->prev ? &sfilter->prev
862
863 seccomp_cache_prepare_bitmap(sfilter,
864 cache_pre
865 SECCOMP_A
866 SECCOMP_A
867
868 #ifdef SECCOMP_ARCH_COMPAT
869 seccomp_cache_prepare_bitmap(sfilter,
870 cache_pre
871 SECCOMP_A
872 SECCOMP_A
873 #endif /* SECCOMP_ARCH_COMPAT */
874 }
875 #endif /* SECCOMP_ARCH_NATIVE */
876
877 /**
878 * seccomp_attach_filter: validate and attach
879 * @flags: flags to change filter behavior
880 * @filter: seccomp filter to add to the curre
881 *
882 * Caller must be holding current->sighand->si
883 *
884 * Returns 0 on success, -ve on error, or
885 * - in TSYNC mode: the pid of a thread whic
886 * seccomp mode or did not have an ancestr
887 * - in NEW_LISTENER mode: the fd of the new
888 */
889 static long seccomp_attach_filter(unsigned int
890 struct secco
891 {
892 unsigned long total_insns;
893 struct seccomp_filter *walker;
894
895 assert_spin_locked(¤t->sighand->
896
897 /* Validate resulting filter length. *
898 total_insns = filter->prog->len;
899 for (walker = current->seccomp.filter;
900 total_insns += walker->prog->l
901 if (total_insns > MAX_INSNS_PER_PATH)
902 return -ENOMEM;
903
904 /* If thread sync has been requested,
905 if (flags & SECCOMP_FILTER_FLAG_TSYNC)
906 int ret;
907
908 ret = seccomp_can_sync_threads
909 if (ret) {
910 if (flags & SECCOMP_FI
911 return -ESRCH;
912 else
913 return ret;
914 }
915 }
916
917 /* Set log flag, if present. */
918 if (flags & SECCOMP_FILTER_FLAG_LOG)
919 filter->log = true;
920
921 /* Set wait killable flag, if present.
922 if (flags & SECCOMP_FILTER_FLAG_WAIT_K
923 filter->wait_killable_recv = t
924
925 /*
926 * If there is an existing filter, mak
927 * task reference.
928 */
929 filter->prev = current->seccomp.filter
930 seccomp_cache_prepare(filter);
931 current->seccomp.filter = filter;
932 atomic_inc(¤t->seccomp.filter_co
933
934 /* Now that the new filter is in place
935 if (flags & SECCOMP_FILTER_FLAG_TSYNC)
936 seccomp_sync_threads(flags);
937
938 return 0;
939 }
940
941 static void __get_seccomp_filter(struct seccom
942 {
943 refcount_inc(&filter->refs);
944 }
945
946 /* get_seccomp_filter - increments the referen
947 void get_seccomp_filter(struct task_struct *ts
948 {
949 struct seccomp_filter *orig = tsk->sec
950 if (!orig)
951 return;
952 __get_seccomp_filter(orig);
953 refcount_inc(&orig->users);
954 }
955
956 #endif /* CONFIG_SECCOMP_FILTER */
957
958 /* For use with seccomp_actions_logged */
959 #define SECCOMP_LOG_KILL_PROCESS (1 <<
960 #define SECCOMP_LOG_KILL_THREAD (1 <<
961 #define SECCOMP_LOG_TRAP (1 <<
962 #define SECCOMP_LOG_ERRNO (1 <<
963 #define SECCOMP_LOG_TRACE (1 <<
964 #define SECCOMP_LOG_LOG (1 <<
965 #define SECCOMP_LOG_ALLOW (1 <<
966 #define SECCOMP_LOG_USER_NOTIF (1 <<
967
968 static u32 seccomp_actions_logged = SECCOMP_LO
969 SECCOMP_LO
970 SECCOMP_LO
971 SECCOMP_LO
972 SECCOMP_LO
973 SECCOMP_LO
974 SECCOMP_LO
975
976 static inline void seccomp_log(unsigned long s
977 bool requested)
978 {
979 bool log = false;
980
981 switch (action) {
982 case SECCOMP_RET_ALLOW:
983 break;
984 case SECCOMP_RET_TRAP:
985 log = requested && seccomp_act
986 break;
987 case SECCOMP_RET_ERRNO:
988 log = requested && seccomp_act
989 break;
990 case SECCOMP_RET_TRACE:
991 log = requested && seccomp_act
992 break;
993 case SECCOMP_RET_USER_NOTIF:
994 log = requested && seccomp_act
995 break;
996 case SECCOMP_RET_LOG:
997 log = seccomp_actions_logged &
998 break;
999 case SECCOMP_RET_KILL_THREAD:
1000 log = seccomp_actions_logged
1001 break;
1002 case SECCOMP_RET_KILL_PROCESS:
1003 default:
1004 log = seccomp_actions_logged
1005 }
1006
1007 /*
1008 * Emit an audit message when the act
1009 * FILTER_FLAG_LOG bit was set. The a
1010 * any action from being logged by re
1011 * seccomp_actions_logged sysctl.
1012 */
1013 if (!log)
1014 return;
1015
1016 audit_seccomp(syscall, signr, action)
1017 }
1018
1019 /*
1020 * Secure computing mode 1 allows only read/w
1021 * To be fully secure this must be combined w
1022 * to limit the stack allocations too.
1023 */
1024 static const int mode1_syscalls[] = {
1025 __NR_seccomp_read, __NR_seccomp_write
1026 -1, /* negative terminated */
1027 };
1028
1029 static void __secure_computing_strict(int thi
1030 {
1031 const int *allowed_syscalls = mode1_s
1032 #ifdef CONFIG_COMPAT
1033 if (in_compat_syscall())
1034 allowed_syscalls = get_compat
1035 #endif
1036 do {
1037 if (*allowed_syscalls == this
1038 return;
1039 } while (*++allowed_syscalls != -1);
1040
1041 #ifdef SECCOMP_DEBUG
1042 dump_stack();
1043 #endif
1044 current->seccomp.mode = SECCOMP_MODE_
1045 seccomp_log(this_syscall, SIGKILL, SE
1046 do_exit(SIGKILL);
1047 }
1048
1049 #ifndef CONFIG_HAVE_ARCH_SECCOMP_FILTER
1050 void secure_computing_strict(int this_syscall
1051 {
1052 int mode = current->seccomp.mode;
1053
1054 if (IS_ENABLED(CONFIG_CHECKPOINT_REST
1055 unlikely(current->ptrace & PT_SUS
1056 return;
1057
1058 if (mode == SECCOMP_MODE_DISABLED)
1059 return;
1060 else if (mode == SECCOMP_MODE_STRICT)
1061 __secure_computing_strict(thi
1062 else
1063 BUG();
1064 }
1065 #else
1066
1067 #ifdef CONFIG_SECCOMP_FILTER
1068 static u64 seccomp_next_notify_id(struct secc
1069 {
1070 /*
1071 * Note: overflow is ok here, the id
1072 * filter.
1073 */
1074 lockdep_assert_held(&filter->notify_l
1075 return filter->notif->next_id++;
1076 }
1077
1078 static void seccomp_handle_addfd(struct secco
1079 {
1080 int fd;
1081
1082 /*
1083 * Remove the notification, and reset
1084 * that it has been handled.
1085 */
1086 list_del_init(&addfd->list);
1087 if (!addfd->setfd)
1088 fd = receive_fd(addfd->file,
1089 else
1090 fd = receive_fd_replace(addfd
1091 addfd->ret = fd;
1092
1093 if (addfd->ioctl_flags & SECCOMP_ADDF
1094 /* If we fail reset and retur
1095 if (fd < 0) {
1096 n->state = SECCOMP_NO
1097 } else {
1098 /* Return the FD we j
1099 n->flags = 0;
1100 n->error = 0;
1101 n->val = fd;
1102 }
1103 }
1104
1105 /*
1106 * Mark the notification as completed
1107 * might be invalidated and we can't
1108 */
1109 complete(&addfd->completion);
1110 }
1111
1112 static bool should_sleep_killable(struct secc
1113 struct secc
1114 {
1115 return match->wait_killable_recv && n
1116 }
1117
1118 static int seccomp_do_user_notification(int t
1119 struc
1120 const
1121 {
1122 int err;
1123 u32 flags = 0;
1124 long ret = 0;
1125 struct seccomp_knotif n = {};
1126 struct seccomp_kaddfd *addfd, *tmp;
1127
1128 mutex_lock(&match->notify_lock);
1129 err = -ENOSYS;
1130 if (!match->notif)
1131 goto out;
1132
1133 n.task = current;
1134 n.state = SECCOMP_NOTIFY_INIT;
1135 n.data = sd;
1136 n.id = seccomp_next_notify_id(match);
1137 init_completion(&n.ready);
1138 list_add_tail(&n.list, &match->notif-
1139 INIT_LIST_HEAD(&n.addfd);
1140
1141 atomic_inc(&match->notif->requests);
1142 if (match->notif->flags & SECCOMP_USE
1143 wake_up_poll_on_current_cpu(&
1144 else
1145 wake_up_poll(&match->wqh, EPO
1146
1147 /*
1148 * This is where we wait for a reply
1149 */
1150 do {
1151 bool wait_killable = should_s
1152
1153 mutex_unlock(&match->notify_l
1154 if (wait_killable)
1155 err = wait_for_comple
1156 else
1157 err = wait_for_comple
1158 mutex_lock(&match->notify_loc
1159
1160 if (err != 0) {
1161 /*
1162 * Check to see if th
1163 * whether we should
1164 */
1165 if (!wait_killable &&
1166 continue;
1167
1168 goto interrupted;
1169 }
1170
1171 addfd = list_first_entry_or_n
1172
1173 /* Check if we were woken up
1174 if (addfd)
1175 seccomp_handle_addfd(
1176
1177 } while (n.state != SECCOMP_NOTIFY_R
1178
1179 ret = n.val;
1180 err = n.error;
1181 flags = n.flags;
1182
1183 interrupted:
1184 /* If there were any pending addfd ca
1185 list_for_each_entry_safe(addfd, tmp,
1186 /* The process went away befo
1187 addfd->ret = -ESRCH;
1188 list_del_init(&addfd->list);
1189 complete(&addfd->completion);
1190 }
1191
1192 /*
1193 * Note that it's possible the listen
1194 * we were notified of a response (or
1195 * re-acquire the lock, so only delet
1196 * notification actually exists.
1197 *
1198 * Also note that this test is only v
1199 * *reattach* to a notifier right now
1200 * keep track of the notif itself and
1201 */
1202 if (match->notif)
1203 list_del(&n.list);
1204 out:
1205 mutex_unlock(&match->notify_lock);
1206
1207 /* Userspace requests to continue the
1208 if (flags & SECCOMP_USER_NOTIF_FLAG_C
1209 return 0;
1210
1211 syscall_set_return_value(current, cur
1212 err, ret);
1213 return -1;
1214 }
1215
1216 static int __seccomp_filter(int this_syscall,
1217 const bool rechec
1218 {
1219 u32 filter_ret, action;
1220 struct seccomp_filter *match = NULL;
1221 int data;
1222 struct seccomp_data sd_local;
1223
1224 /*
1225 * Make sure that any changes to mode
1226 * been seen after SYSCALL_WORK_SECCO
1227 */
1228 smp_rmb();
1229
1230 if (!sd) {
1231 populate_seccomp_data(&sd_loc
1232 sd = &sd_local;
1233 }
1234
1235 filter_ret = seccomp_run_filters(sd,
1236 data = filter_ret & SECCOMP_RET_DATA;
1237 action = filter_ret & SECCOMP_RET_ACT
1238
1239 switch (action) {
1240 case SECCOMP_RET_ERRNO:
1241 /* Set low-order bits as an e
1242 if (data > MAX_ERRNO)
1243 data = MAX_ERRNO;
1244 syscall_set_return_value(curr
1245 -dat
1246 goto skip;
1247
1248 case SECCOMP_RET_TRAP:
1249 /* Show the handler the origi
1250 syscall_rollback(current, cur
1251 /* Let the filter pass back 1
1252 force_sig_seccomp(this_syscal
1253 goto skip;
1254
1255 case SECCOMP_RET_TRACE:
1256 /* We've been put in this sta
1257 if (recheck_after_trace)
1258 return 0;
1259
1260 /* ENOSYS these calls if ther
1261 if (!ptrace_event_enabled(cur
1262 syscall_set_return_va
1263
1264
1265 goto skip;
1266 }
1267
1268 /* Allow the BPF to provide t
1269 ptrace_event(PTRACE_EVENT_SEC
1270 /*
1271 * The delivery of a fatal si
1272 * notification may silently
1273 * which could leave us with
1274 * syscall that the tracer wo
1275 * changed. Since the process
1276 * force the syscall to be sk
1277 * kill the process and corre
1278 * notifications.
1279 */
1280 if (fatal_signal_pending(curr
1281 goto skip;
1282 /* Check if the tracer forced
1283 this_syscall = syscall_get_nr
1284 if (this_syscall < 0)
1285 goto skip;
1286
1287 /*
1288 * Recheck the syscall, since
1289 * intentionally uses a NULL
1290 * a reload of all registers.
1291 * a skip would have already
1292 */
1293 if (__seccomp_filter(this_sys
1294 return -1;
1295
1296 return 0;
1297
1298 case SECCOMP_RET_USER_NOTIF:
1299 if (seccomp_do_user_notificat
1300 goto skip;
1301
1302 return 0;
1303
1304 case SECCOMP_RET_LOG:
1305 seccomp_log(this_syscall, 0,
1306 return 0;
1307
1308 case SECCOMP_RET_ALLOW:
1309 /*
1310 * Note that the "match" filt
1311 * this action since SECCOMP_
1312 * state in seccomp_run_filte
1313 */
1314 return 0;
1315
1316 case SECCOMP_RET_KILL_THREAD:
1317 case SECCOMP_RET_KILL_PROCESS:
1318 default:
1319 current->seccomp.mode = SECCO
1320 seccomp_log(this_syscall, SIG
1321 /* Dump core only if this is
1322 if (action != SECCOMP_RET_KIL
1323 (atomic_read(¤t->si
1324 /* Show the original
1325 syscall_rollback(curr
1326 /* Trigger a coredump
1327 force_sig_seccomp(thi
1328 } else {
1329 do_exit(SIGSYS);
1330 }
1331 return -1; /* skip the syscal
1332 }
1333
1334 unreachable();
1335
1336 skip:
1337 seccomp_log(this_syscall, 0, action,
1338 return -1;
1339 }
1340 #else
1341 static int __seccomp_filter(int this_syscall,
1342 const bool rechec
1343 {
1344 BUG();
1345
1346 return -1;
1347 }
1348 #endif
1349
1350 int __secure_computing(const struct seccomp_d
1351 {
1352 int mode = current->seccomp.mode;
1353 int this_syscall;
1354
1355 if (IS_ENABLED(CONFIG_CHECKPOINT_REST
1356 unlikely(current->ptrace & PT_SUS
1357 return 0;
1358
1359 this_syscall = sd ? sd->nr :
1360 syscall_get_nr(current, curre
1361
1362 switch (mode) {
1363 case SECCOMP_MODE_STRICT:
1364 __secure_computing_strict(thi
1365 return 0;
1366 case SECCOMP_MODE_FILTER:
1367 return __seccomp_filter(this_
1368 /* Surviving SECCOMP_RET_KILL_* must
1369 case SECCOMP_MODE_DEAD:
1370 WARN_ON_ONCE(1);
1371 do_exit(SIGKILL);
1372 return -1;
1373 default:
1374 BUG();
1375 }
1376 }
1377 #endif /* CONFIG_HAVE_ARCH_SECCOMP_FILTER */
1378
1379 long prctl_get_seccomp(void)
1380 {
1381 return current->seccomp.mode;
1382 }
1383
1384 /**
1385 * seccomp_set_mode_strict: internal function
1386 *
1387 * Once current->seccomp.mode is non-zero, it
1388 *
1389 * Returns 0 on success or -EINVAL on failure
1390 */
1391 static long seccomp_set_mode_strict(void)
1392 {
1393 const unsigned long seccomp_mode = SE
1394 long ret = -EINVAL;
1395
1396 spin_lock_irq(¤t->sighand->sigl
1397
1398 if (!seccomp_may_assign_mode(seccomp_
1399 goto out;
1400
1401 #ifdef TIF_NOTSC
1402 disable_TSC();
1403 #endif
1404 seccomp_assign_mode(current, seccomp_
1405 ret = 0;
1406
1407 out:
1408 spin_unlock_irq(¤t->sighand->si
1409
1410 return ret;
1411 }
1412
1413 #ifdef CONFIG_SECCOMP_FILTER
1414 static void seccomp_notify_free(struct seccom
1415 {
1416 kfree(filter->notif);
1417 filter->notif = NULL;
1418 }
1419
1420 static void seccomp_notify_detach(struct secc
1421 {
1422 struct seccomp_knotif *knotif;
1423
1424 if (!filter)
1425 return;
1426
1427 mutex_lock(&filter->notify_lock);
1428
1429 /*
1430 * If this file is being closed becau
1431 * died, let's wake everyone up who w
1432 */
1433 list_for_each_entry(knotif, &filter->
1434 if (knotif->state == SECCOMP_
1435 continue;
1436
1437 knotif->state = SECCOMP_NOTIF
1438 knotif->error = -ENOSYS;
1439 knotif->val = 0;
1440
1441 /*
1442 * We do not need to wake up
1443 * the notifier will do that
1444 * like a standard reply.
1445 */
1446 complete(&knotif->ready);
1447 }
1448
1449 seccomp_notify_free(filter);
1450 mutex_unlock(&filter->notify_lock);
1451 }
1452
1453 static int seccomp_notify_release(struct inod
1454 {
1455 struct seccomp_filter *filter = file-
1456
1457 seccomp_notify_detach(filter);
1458 __put_seccomp_filter(filter);
1459 return 0;
1460 }
1461
1462 /* must be called with notif_lock held */
1463 static inline struct seccomp_knotif *
1464 find_notification(struct seccomp_filter *filt
1465 {
1466 struct seccomp_knotif *cur;
1467
1468 lockdep_assert_held(&filter->notify_l
1469
1470 list_for_each_entry(cur, &filter->not
1471 if (cur->id == id)
1472 return cur;
1473 }
1474
1475 return NULL;
1476 }
1477
1478 static int recv_wake_function(wait_queue_entr
1479 void *key)
1480 {
1481 /* Avoid a wakeup if event not intere
1482 if (key && !(key_to_poll(key) & (EPOL
1483 return 0;
1484 return autoremove_wake_function(wait,
1485 }
1486
1487 static int recv_wait_event(struct seccomp_fil
1488 {
1489 DEFINE_WAIT_FUNC(wait, recv_wake_func
1490 int ret;
1491
1492 if (refcount_read(&filter->users) ==
1493 return 0;
1494
1495 if (atomic_dec_if_positive(&filter->n
1496 return 0;
1497
1498 for (;;) {
1499 ret = prepare_to_wait_event(&
1500
1501 if (atomic_dec_if_positive(&f
1502 break;
1503 if (refcount_read(&filter->us
1504 break;
1505
1506 if (ret)
1507 return ret;
1508
1509 schedule();
1510 }
1511 finish_wait(&filter->wqh, &wait);
1512 return 0;
1513 }
1514
1515 static long seccomp_notify_recv(struct seccom
1516 void __user *
1517 {
1518 struct seccomp_knotif *knotif = NULL,
1519 struct seccomp_notif unotif;
1520 ssize_t ret;
1521
1522 /* Verify that we're not given garbag
1523 ret = check_zeroed_user(buf, sizeof(u
1524 if (ret < 0)
1525 return ret;
1526 if (!ret)
1527 return -EINVAL;
1528
1529 memset(&unotif, 0, sizeof(unotif));
1530
1531 ret = recv_wait_event(filter);
1532 if (ret < 0)
1533 return ret;
1534
1535 mutex_lock(&filter->notify_lock);
1536 list_for_each_entry(cur, &filter->not
1537 if (cur->state == SECCOMP_NOT
1538 knotif = cur;
1539 break;
1540 }
1541 }
1542
1543 /*
1544 * If we didn't find a notification,
1545 * interrupted by a fatal signal betw
1546 * when we were able to acquire the r
1547 */
1548 if (!knotif) {
1549 ret = -ENOENT;
1550 goto out;
1551 }
1552
1553 unotif.id = knotif->id;
1554 unotif.pid = task_pid_vnr(knotif->tas
1555 unotif.data = *(knotif->data);
1556
1557 knotif->state = SECCOMP_NOTIFY_SENT;
1558 wake_up_poll(&filter->wqh, EPOLLOUT |
1559 ret = 0;
1560 out:
1561 mutex_unlock(&filter->notify_lock);
1562
1563 if (ret == 0 && copy_to_user(buf, &un
1564 ret = -EFAULT;
1565
1566 /*
1567 * Userspace screwed up. To m
1568 * notification alive, let's
1569 * may have died when we rele
1570 * sure it's still around.
1571 */
1572 mutex_lock(&filter->notify_lo
1573 knotif = find_notification(fi
1574 if (knotif) {
1575 /* Reset the process
1576 if (should_sleep_kill
1577 complete(&kno
1578 knotif->state = SECCO
1579 atomic_inc(&filter->n
1580 wake_up_poll(&filter-
1581 }
1582 mutex_unlock(&filter->notify_
1583 }
1584
1585 return ret;
1586 }
1587
1588 static long seccomp_notify_send(struct seccom
1589 void __user *
1590 {
1591 struct seccomp_notif_resp resp = {};
1592 struct seccomp_knotif *knotif;
1593 long ret;
1594
1595 if (copy_from_user(&resp, buf, sizeof
1596 return -EFAULT;
1597
1598 if (resp.flags & ~SECCOMP_USER_NOTIF_
1599 return -EINVAL;
1600
1601 if ((resp.flags & SECCOMP_USER_NOTIF_
1602 (resp.error || resp.val))
1603 return -EINVAL;
1604
1605 ret = mutex_lock_interruptible(&filte
1606 if (ret < 0)
1607 return ret;
1608
1609 knotif = find_notification(filter, re
1610 if (!knotif) {
1611 ret = -ENOENT;
1612 goto out;
1613 }
1614
1615 /* Allow exactly one reply. */
1616 if (knotif->state != SECCOMP_NOTIFY_S
1617 ret = -EINPROGRESS;
1618 goto out;
1619 }
1620
1621 ret = 0;
1622 knotif->state = SECCOMP_NOTIFY_REPLIE
1623 knotif->error = resp.error;
1624 knotif->val = resp.val;
1625 knotif->flags = resp.flags;
1626 if (filter->notif->flags & SECCOMP_US
1627 complete_on_current_cpu(&knot
1628 else
1629 complete(&knotif->ready);
1630 out:
1631 mutex_unlock(&filter->notify_lock);
1632 return ret;
1633 }
1634
1635 static long seccomp_notify_id_valid(struct se
1636 void __us
1637 {
1638 struct seccomp_knotif *knotif;
1639 u64 id;
1640 long ret;
1641
1642 if (copy_from_user(&id, buf, sizeof(i
1643 return -EFAULT;
1644
1645 ret = mutex_lock_interruptible(&filte
1646 if (ret < 0)
1647 return ret;
1648
1649 knotif = find_notification(filter, id
1650 if (knotif && knotif->state == SECCOM
1651 ret = 0;
1652 else
1653 ret = -ENOENT;
1654
1655 mutex_unlock(&filter->notify_lock);
1656 return ret;
1657 }
1658
1659 static long seccomp_notify_set_flags(struct s
1660 unsigned
1661 {
1662 long ret;
1663
1664 if (flags & ~SECCOMP_USER_NOTIF_FD_SY
1665 return -EINVAL;
1666
1667 ret = mutex_lock_interruptible(&filte
1668 if (ret < 0)
1669 return ret;
1670 filter->notif->flags = flags;
1671 mutex_unlock(&filter->notify_lock);
1672 return 0;
1673 }
1674
1675 static long seccomp_notify_addfd(struct secco
1676 struct secco
1677 unsigned int
1678 {
1679 struct seccomp_notif_addfd addfd;
1680 struct seccomp_knotif *knotif;
1681 struct seccomp_kaddfd kaddfd;
1682 int ret;
1683
1684 BUILD_BUG_ON(sizeof(addfd) < SECCOMP_
1685 BUILD_BUG_ON(sizeof(addfd) != SECCOMP
1686
1687 if (size < SECCOMP_NOTIFY_ADDFD_SIZE_
1688 return -EINVAL;
1689
1690 ret = copy_struct_from_user(&addfd, s
1691 if (ret)
1692 return ret;
1693
1694 if (addfd.newfd_flags & ~O_CLOEXEC)
1695 return -EINVAL;
1696
1697 if (addfd.flags & ~(SECCOMP_ADDFD_FLA
1698 return -EINVAL;
1699
1700 if (addfd.newfd && !(addfd.flags & SE
1701 return -EINVAL;
1702
1703 kaddfd.file = fget(addfd.srcfd);
1704 if (!kaddfd.file)
1705 return -EBADF;
1706
1707 kaddfd.ioctl_flags = addfd.flags;
1708 kaddfd.flags = addfd.newfd_flags;
1709 kaddfd.setfd = addfd.flags & SECCOMP_
1710 kaddfd.fd = addfd.newfd;
1711 init_completion(&kaddfd.completion);
1712
1713 ret = mutex_lock_interruptible(&filte
1714 if (ret < 0)
1715 goto out;
1716
1717 knotif = find_notification(filter, ad
1718 if (!knotif) {
1719 ret = -ENOENT;
1720 goto out_unlock;
1721 }
1722
1723 /*
1724 * We do not want to allow for FD inj
1725 * notification has been picked up by
1726 * the notification has been replied
1727 */
1728 if (knotif->state != SECCOMP_NOTIFY_S
1729 ret = -EINPROGRESS;
1730 goto out_unlock;
1731 }
1732
1733 if (addfd.flags & SECCOMP_ADDFD_FLAG_
1734 /*
1735 * Disallow queuing an atomic
1736 * some addfd requests still
1737 *
1738 * There is no clear reason t
1739 * the loop on the other side
1740 */
1741 if (!list_empty(&knotif->addf
1742 ret = -EBUSY;
1743 goto out_unlock;
1744 }
1745
1746 /* Allow exactly only one rep
1747 knotif->state = SECCOMP_NOTIF
1748 }
1749
1750 list_add(&kaddfd.list, &knotif->addfd
1751 complete(&knotif->ready);
1752 mutex_unlock(&filter->notify_lock);
1753
1754 /* Now we wait for it to be processed
1755 ret = wait_for_completion_interruptib
1756 if (ret == 0) {
1757 /*
1758 * We had a successful comple
1759 * removed us from the addfd
1760 * wait_for_completion_interr
1761 * success that lets us read
1762 * locking.
1763 */
1764 ret = kaddfd.ret;
1765 goto out;
1766 }
1767
1768 mutex_lock(&filter->notify_lock);
1769 /*
1770 * Even though we were woken up by a
1771 * completion, a completion may have
1772 *
1773 * We need to check again if the addf
1774 * and if not, we will remove it from
1775 */
1776 if (list_empty(&kaddfd.list))
1777 ret = kaddfd.ret;
1778 else
1779 list_del(&kaddfd.list);
1780
1781 out_unlock:
1782 mutex_unlock(&filter->notify_lock);
1783 out:
1784 fput(kaddfd.file);
1785
1786 return ret;
1787 }
1788
1789 static long seccomp_notify_ioctl(struct file
1790 unsigned lon
1791 {
1792 struct seccomp_filter *filter = file-
1793 void __user *buf = (void __user *)arg
1794
1795 /* Fixed-size ioctls */
1796 switch (cmd) {
1797 case SECCOMP_IOCTL_NOTIF_RECV:
1798 return seccomp_notify_recv(fi
1799 case SECCOMP_IOCTL_NOTIF_SEND:
1800 return seccomp_notify_send(fi
1801 case SECCOMP_IOCTL_NOTIF_ID_VALID_WRO
1802 case SECCOMP_IOCTL_NOTIF_ID_VALID:
1803 return seccomp_notify_id_vali
1804 case SECCOMP_IOCTL_NOTIF_SET_FLAGS:
1805 return seccomp_notify_set_fla
1806 }
1807
1808 /* Extensible Argument ioctls */
1809 #define EA_IOCTL(cmd) ((cmd) & ~(IOC_INOUT
1810 switch (EA_IOCTL(cmd)) {
1811 case EA_IOCTL(SECCOMP_IOCTL_NOTIF_ADD
1812 return seccomp_notify_addfd(f
1813 default:
1814 return -EINVAL;
1815 }
1816 }
1817
1818 static __poll_t seccomp_notify_poll(struct fi
1819 struct po
1820 {
1821 struct seccomp_filter *filter = file-
1822 __poll_t ret = 0;
1823 struct seccomp_knotif *cur;
1824
1825 poll_wait(file, &filter->wqh, poll_ta
1826
1827 if (mutex_lock_interruptible(&filter-
1828 return EPOLLERR;
1829
1830 list_for_each_entry(cur, &filter->not
1831 if (cur->state == SECCOMP_NOT
1832 ret |= EPOLLIN | EPOL
1833 if (cur->state == SECCOMP_NOT
1834 ret |= EPOLLOUT | EPO
1835 if ((ret & EPOLLIN) && (ret &
1836 break;
1837 }
1838
1839 mutex_unlock(&filter->notify_lock);
1840
1841 if (refcount_read(&filter->users) ==
1842 ret |= EPOLLHUP;
1843
1844 return ret;
1845 }
1846
1847 static const struct file_operations seccomp_n
1848 .poll = seccomp_notify_poll,
1849 .release = seccomp_notify_release,
1850 .unlocked_ioctl = seccomp_notify_ioct
1851 .compat_ioctl = seccomp_notify_ioctl,
1852 };
1853
1854 static struct file *init_listener(struct secc
1855 {
1856 struct file *ret;
1857
1858 ret = ERR_PTR(-ENOMEM);
1859 filter->notif = kzalloc(sizeof(*(filt
1860 if (!filter->notif)
1861 goto out;
1862
1863 filter->notif->next_id = get_random_u
1864 INIT_LIST_HEAD(&filter->notif->notifi
1865
1866 ret = anon_inode_getfile("seccomp not
1867 filter, O_RD
1868 if (IS_ERR(ret))
1869 goto out_notif;
1870
1871 /* The file has a reference to it now
1872 __get_seccomp_filter(filter);
1873
1874 out_notif:
1875 if (IS_ERR(ret))
1876 seccomp_notify_free(filter);
1877 out:
1878 return ret;
1879 }
1880
1881 /*
1882 * Does @new_child have a listener while an a
1883 * If so, we'll want to reject this filter.
1884 * This only has to be tested for the current
1885 * because TSYNC installs @child with the sam
1886 * Note that @new_child is not hooked up to i
1887 * we use current->seccomp.filter.
1888 */
1889 static bool has_duplicate_listener(struct sec
1890 {
1891 struct seccomp_filter *cur;
1892
1893 /* must be protected against concurre
1894 lockdep_assert_held(¤t->sighand
1895
1896 if (!new_child->notif)
1897 return false;
1898 for (cur = current->seccomp.filter; c
1899 if (cur->notif)
1900 return true;
1901 }
1902
1903 return false;
1904 }
1905
1906 /**
1907 * seccomp_set_mode_filter: internal function
1908 * @flags: flags to change filter behavior
1909 * @filter: struct sock_fprog containing filt
1910 *
1911 * This function may be called repeatedly to
1912 * Every filter successfully installed will b
1913 * for each system call the task makes.
1914 *
1915 * Once current->seccomp.mode is non-zero, it
1916 *
1917 * Returns 0 on success or -EINVAL on failure
1918 */
1919 static long seccomp_set_mode_filter(unsigned
1920 const cha
1921 {
1922 const unsigned long seccomp_mode = SE
1923 struct seccomp_filter *prepared = NUL
1924 long ret = -EINVAL;
1925 int listener = -1;
1926 struct file *listener_f = NULL;
1927
1928 /* Validate flags. */
1929 if (flags & ~SECCOMP_FILTER_FLAG_MASK
1930 return -EINVAL;
1931
1932 /*
1933 * In the successful case, NEW_LISTEN
1934 * But in the failure case, TSYNC ret
1935 * combine these two flags, there's n
1936 * succeeded or failed. So, let's dis
1937 * has not explicitly requested no er
1938 */
1939 if ((flags & SECCOMP_FILTER_FLAG_TSYN
1940 (flags & SECCOMP_FILTER_FLAG_NEW_
1941 ((flags & SECCOMP_FILTER_FLAG_TSY
1942 return -EINVAL;
1943
1944 /*
1945 * The SECCOMP_FILTER_FLAG_WAIT_KILLA
1946 * without the SECCOMP_FILTER_FLAG_NE
1947 */
1948 if ((flags & SECCOMP_FILTER_FLAG_WAIT
1949 ((flags & SECCOMP_FILTER_FLAG_NEW
1950 return -EINVAL;
1951
1952 /* Prepare the new filter before hold
1953 prepared = seccomp_prepare_user_filte
1954 if (IS_ERR(prepared))
1955 return PTR_ERR(prepared);
1956
1957 if (flags & SECCOMP_FILTER_FLAG_NEW_L
1958 listener = get_unused_fd_flag
1959 if (listener < 0) {
1960 ret = listener;
1961 goto out_free;
1962 }
1963
1964 listener_f = init_listener(pr
1965 if (IS_ERR(listener_f)) {
1966 put_unused_fd(listene
1967 ret = PTR_ERR(listene
1968 goto out_free;
1969 }
1970 }
1971
1972 /*
1973 * Make sure we cannot change seccomp
1974 * while another thread is in the mid
1975 */
1976 if (flags & SECCOMP_FILTER_FLAG_TSYNC
1977 mutex_lock_killable(¤t->sig
1978 goto out_put_fd;
1979
1980 spin_lock_irq(¤t->sighand->sigl
1981
1982 if (!seccomp_may_assign_mode(seccomp_
1983 goto out;
1984
1985 if (has_duplicate_listener(prepared))
1986 ret = -EBUSY;
1987 goto out;
1988 }
1989
1990 ret = seccomp_attach_filter(flags, pr
1991 if (ret)
1992 goto out;
1993 /* Do not free the successfully attac
1994 prepared = NULL;
1995
1996 seccomp_assign_mode(current, seccomp_
1997 out:
1998 spin_unlock_irq(¤t->sighand->si
1999 if (flags & SECCOMP_FILTER_FLAG_TSYNC
2000 mutex_unlock(¤t->signal
2001 out_put_fd:
2002 if (flags & SECCOMP_FILTER_FLAG_NEW_L
2003 if (ret) {
2004 listener_f->private_d
2005 fput(listener_f);
2006 put_unused_fd(listene
2007 seccomp_notify_detach
2008 } else {
2009 fd_install(listener,
2010 ret = listener;
2011 }
2012 }
2013 out_free:
2014 seccomp_filter_free(prepared);
2015 return ret;
2016 }
2017 #else
2018 static inline long seccomp_set_mode_filter(un
2019 co
2020 {
2021 return -EINVAL;
2022 }
2023 #endif
2024
2025 static long seccomp_get_action_avail(const ch
2026 {
2027 u32 action;
2028
2029 if (copy_from_user(&action, uaction,
2030 return -EFAULT;
2031
2032 switch (action) {
2033 case SECCOMP_RET_KILL_PROCESS:
2034 case SECCOMP_RET_KILL_THREAD:
2035 case SECCOMP_RET_TRAP:
2036 case SECCOMP_RET_ERRNO:
2037 case SECCOMP_RET_USER_NOTIF:
2038 case SECCOMP_RET_TRACE:
2039 case SECCOMP_RET_LOG:
2040 case SECCOMP_RET_ALLOW:
2041 break;
2042 default:
2043 return -EOPNOTSUPP;
2044 }
2045
2046 return 0;
2047 }
2048
2049 static long seccomp_get_notif_sizes(void __us
2050 {
2051 struct seccomp_notif_sizes sizes = {
2052 .seccomp_notif = sizeof(struc
2053 .seccomp_notif_resp = sizeof(
2054 .seccomp_data = sizeof(struct
2055 };
2056
2057 if (copy_to_user(usizes, &sizes, size
2058 return -EFAULT;
2059
2060 return 0;
2061 }
2062
2063 /* Common entry point for both prctl and sysc
2064 static long do_seccomp(unsigned int op, unsig
2065 void __user *uargs)
2066 {
2067 switch (op) {
2068 case SECCOMP_SET_MODE_STRICT:
2069 if (flags != 0 || uargs != NU
2070 return -EINVAL;
2071 return seccomp_set_mode_stric
2072 case SECCOMP_SET_MODE_FILTER:
2073 return seccomp_set_mode_filte
2074 case SECCOMP_GET_ACTION_AVAIL:
2075 if (flags != 0)
2076 return -EINVAL;
2077
2078 return seccomp_get_action_ava
2079 case SECCOMP_GET_NOTIF_SIZES:
2080 if (flags != 0)
2081 return -EINVAL;
2082
2083 return seccomp_get_notif_size
2084 default:
2085 return -EINVAL;
2086 }
2087 }
2088
2089 SYSCALL_DEFINE3(seccomp, unsigned int, op, un
2090 void __user *, uargs
2091 {
2092 return do_seccomp(op, flags, uargs);
2093 }
2094
2095 /**
2096 * prctl_set_seccomp: configures current->sec
2097 * @seccomp_mode: requested mode to use
2098 * @filter: optional struct sock_fprog for us
2099 *
2100 * Returns 0 on success or -EINVAL on failure
2101 */
2102 long prctl_set_seccomp(unsigned long seccomp_
2103 {
2104 unsigned int op;
2105 void __user *uargs;
2106
2107 switch (seccomp_mode) {
2108 case SECCOMP_MODE_STRICT:
2109 op = SECCOMP_SET_MODE_STRICT;
2110 /*
2111 * Setting strict mode throug
2112 * so make sure it is always
2113 * check in do_seccomp().
2114 */
2115 uargs = NULL;
2116 break;
2117 case SECCOMP_MODE_FILTER:
2118 op = SECCOMP_SET_MODE_FILTER;
2119 uargs = filter;
2120 break;
2121 default:
2122 return -EINVAL;
2123 }
2124
2125 /* prctl interface doesn't have flags
2126 return do_seccomp(op, 0, uargs);
2127 }
2128
2129 #if defined(CONFIG_SECCOMP_FILTER) && defined
2130 static struct seccomp_filter *get_nth_filter(
2131
2132 {
2133 struct seccomp_filter *orig, *filter;
2134 unsigned long count;
2135
2136 /*
2137 * Note: this is only correct because
2138 * tracer of the task, otherwise lock
2139 */
2140 spin_lock_irq(&task->sighand->siglock
2141
2142 if (task->seccomp.mode != SECCOMP_MOD
2143 spin_unlock_irq(&task->sighan
2144 return ERR_PTR(-EINVAL);
2145 }
2146
2147 orig = task->seccomp.filter;
2148 __get_seccomp_filter(orig);
2149 spin_unlock_irq(&task->sighand->siglo
2150
2151 count = 0;
2152 for (filter = orig; filter; filter =
2153 count++;
2154
2155 if (filter_off >= count) {
2156 filter = ERR_PTR(-ENOENT);
2157 goto out;
2158 }
2159
2160 count -= filter_off;
2161 for (filter = orig; filter && count >
2162 count--;
2163
2164 if (WARN_ON(count != 1 || !filter)) {
2165 filter = ERR_PTR(-ENOENT);
2166 goto out;
2167 }
2168
2169 __get_seccomp_filter(filter);
2170
2171 out:
2172 __put_seccomp_filter(orig);
2173 return filter;
2174 }
2175
2176 long seccomp_get_filter(struct task_struct *t
2177 void __user *data)
2178 {
2179 struct seccomp_filter *filter;
2180 struct sock_fprog_kern *fprog;
2181 long ret;
2182
2183 if (!capable(CAP_SYS_ADMIN) ||
2184 current->seccomp.mode != SECCOMP_
2185 return -EACCES;
2186 }
2187
2188 filter = get_nth_filter(task, filter_
2189 if (IS_ERR(filter))
2190 return PTR_ERR(filter);
2191
2192 fprog = filter->prog->orig_prog;
2193 if (!fprog) {
2194 /* This must be a new non-cBP
2195 * every cBPF filter's orig_p
2196 * CONFIG_CHECKPOINT_RESTORE
2197 */
2198 ret = -EMEDIUMTYPE;
2199 goto out;
2200 }
2201
2202 ret = fprog->len;
2203 if (!data)
2204 goto out;
2205
2206 if (copy_to_user(data, fprog->filter,
2207 ret = -EFAULT;
2208
2209 out:
2210 __put_seccomp_filter(filter);
2211 return ret;
2212 }
2213
2214 long seccomp_get_metadata(struct task_struct
2215 unsigned long size,
2216 {
2217 long ret;
2218 struct seccomp_filter *filter;
2219 struct seccomp_metadata kmd = {};
2220
2221 if (!capable(CAP_SYS_ADMIN) ||
2222 current->seccomp.mode != SECCOMP_
2223 return -EACCES;
2224 }
2225
2226 size = min_t(unsigned long, size, siz
2227
2228 if (size < sizeof(kmd.filter_off))
2229 return -EINVAL;
2230
2231 if (copy_from_user(&kmd.filter_off, d
2232 return -EFAULT;
2233
2234 filter = get_nth_filter(task, kmd.fil
2235 if (IS_ERR(filter))
2236 return PTR_ERR(filter);
2237
2238 if (filter->log)
2239 kmd.flags |= SECCOMP_FILTER_F
2240
2241 ret = size;
2242 if (copy_to_user(data, &kmd, size))
2243 ret = -EFAULT;
2244
2245 __put_seccomp_filter(filter);
2246 return ret;
2247 }
2248 #endif
2249
2250 #ifdef CONFIG_SYSCTL
2251
2252 /* Human readable action names for friendly s
2253 #define SECCOMP_RET_KILL_PROCESS_NAME "kill
2254 #define SECCOMP_RET_KILL_THREAD_NAME "kill
2255 #define SECCOMP_RET_TRAP_NAME "trap
2256 #define SECCOMP_RET_ERRNO_NAME "errn
2257 #define SECCOMP_RET_USER_NOTIF_NAME "user
2258 #define SECCOMP_RET_TRACE_NAME "trac
2259 #define SECCOMP_RET_LOG_NAME "log"
2260 #define SECCOMP_RET_ALLOW_NAME "allo
2261
2262 static const char seccomp_actions_avail[] =
2263 SECCOMP_RET_K
2264 SECCOMP_RET_K
2265 SECCOMP_RET_T
2266 SECCOMP_RET_E
2267 SECCOMP_RET_U
2268 SECCOMP_RET_T
2269 SECCOMP_RET_L
2270 SECCOMP_RET_A
2271
2272 struct seccomp_log_name {
2273 u32 log;
2274 const char *name;
2275 };
2276
2277 static const struct seccomp_log_name seccomp_
2278 { SECCOMP_LOG_KILL_PROCESS, SECCOMP_R
2279 { SECCOMP_LOG_KILL_THREAD, SECCOMP_RE
2280 { SECCOMP_LOG_TRAP, SECCOMP_RET_TRAP_
2281 { SECCOMP_LOG_ERRNO, SECCOMP_RET_ERRN
2282 { SECCOMP_LOG_USER_NOTIF, SECCOMP_RET
2283 { SECCOMP_LOG_TRACE, SECCOMP_RET_TRAC
2284 { SECCOMP_LOG_LOG, SECCOMP_RET_LOG_NA
2285 { SECCOMP_LOG_ALLOW, SECCOMP_RET_ALLO
2286 { }
2287 };
2288
2289 static bool seccomp_names_from_actions_logged
2290
2291
2292 {
2293 const struct seccomp_log_name *cur;
2294 bool append_sep = false;
2295
2296 for (cur = seccomp_log_names; cur->na
2297 ssize_t ret;
2298
2299 if (!(actions_logged & cur->l
2300 continue;
2301
2302 if (append_sep) {
2303 ret = strscpy(names,
2304 if (ret < 0)
2305 return false;
2306
2307 names += ret;
2308 size -= ret;
2309 } else
2310 append_sep = true;
2311
2312 ret = strscpy(names, cur->nam
2313 if (ret < 0)
2314 return false;
2315
2316 names += ret;
2317 size -= ret;
2318 }
2319
2320 return true;
2321 }
2322
2323 static bool seccomp_action_logged_from_name(u
2324 c
2325 {
2326 const struct seccomp_log_name *cur;
2327
2328 for (cur = seccomp_log_names; cur->na
2329 if (!strcmp(cur->name, name))
2330 *action_logged = cur-
2331 return true;
2332 }
2333 }
2334
2335 return false;
2336 }
2337
2338 static bool seccomp_actions_logged_from_names
2339 {
2340 char *name;
2341
2342 *actions_logged = 0;
2343 while ((name = strsep(&names, " ")) &
2344 u32 action_logged = 0;
2345
2346 if (!seccomp_action_logged_fr
2347 return false;
2348
2349 *actions_logged |= action_log
2350 }
2351
2352 return true;
2353 }
2354
2355 static int read_actions_logged(const struct c
2356 size_t *lenp,
2357 {
2358 char names[sizeof(seccomp_actions_ava
2359 struct ctl_table table;
2360
2361 memset(names, 0, sizeof(names));
2362
2363 if (!seccomp_names_from_actions_logge
2364
2365 return -EINVAL;
2366
2367 table = *ro_table;
2368 table.data = names;
2369 table.maxlen = sizeof(names);
2370 return proc_dostring(&table, 0, buffe
2371 }
2372
2373 static int write_actions_logged(const struct
2374 size_t *lenp,
2375 {
2376 char names[sizeof(seccomp_actions_ava
2377 struct ctl_table table;
2378 int ret;
2379
2380 if (!capable(CAP_SYS_ADMIN))
2381 return -EPERM;
2382
2383 memset(names, 0, sizeof(names));
2384
2385 table = *ro_table;
2386 table.data = names;
2387 table.maxlen = sizeof(names);
2388 ret = proc_dostring(&table, 1, buffer
2389 if (ret)
2390 return ret;
2391
2392 if (!seccomp_actions_logged_from_name
2393 return -EINVAL;
2394
2395 if (*actions_logged & SECCOMP_LOG_ALL
2396 return -EINVAL;
2397
2398 seccomp_actions_logged = *actions_log
2399 return 0;
2400 }
2401
2402 static void audit_actions_logged(u32 actions_
2403 int ret)
2404 {
2405 char names[sizeof(seccomp_actions_ava
2406 char old_names[sizeof(seccomp_actions
2407 const char *new = names;
2408 const char *old = old_names;
2409
2410 if (!audit_enabled)
2411 return;
2412
2413 memset(names, 0, sizeof(names));
2414 memset(old_names, 0, sizeof(old_names
2415
2416 if (ret)
2417 new = "?";
2418 else if (!actions_logged)
2419 new = "(none)";
2420 else if (!seccomp_names_from_actions_
2421
2422 new = "?";
2423
2424 if (!old_actions_logged)
2425 old = "(none)";
2426 else if (!seccomp_names_from_actions_
2427
2428
2429 old = "?";
2430
2431 return audit_seccomp_actions_logged(n
2432 }
2433
2434 static int seccomp_actions_logged_handler(con
2435 voi
2436 lof
2437 {
2438 int ret;
2439
2440 if (write) {
2441 u32 actions_logged = 0;
2442 u32 old_actions_logged = secc
2443
2444 ret = write_actions_logged(ro
2445 &a
2446 audit_actions_logged(actions_
2447 } else
2448 ret = read_actions_logged(ro_
2449
2450 return ret;
2451 }
2452
2453 static struct ctl_table seccomp_sysctl_table[
2454 {
2455 .procname = "actions_av
2456 .data = (void *) &s
2457 .maxlen = sizeof(secc
2458 .mode = 0444,
2459 .proc_handler = proc_dostri
2460 },
2461 {
2462 .procname = "actions_lo
2463 .mode = 0644,
2464 .proc_handler = seccomp_act
2465 },
2466 };
2467
2468 static int __init seccomp_sysctl_init(void)
2469 {
2470 register_sysctl_init("kernel/seccomp"
2471 return 0;
2472 }
2473
2474 device_initcall(seccomp_sysctl_init)
2475
2476 #endif /* CONFIG_SYSCTL */
2477
2478 #ifdef CONFIG_SECCOMP_CACHE_DEBUG
2479 /* Currently CONFIG_SECCOMP_CACHE_DEBUG impli
2480 static void proc_pid_seccomp_cache_arch(struc
2481 const
2482 {
2483 int nr;
2484
2485 for (nr = 0; nr < bitmap_size; nr++)
2486 bool cached = test_bit(nr, bi
2487 char *status = cached ? "ALLO
2488
2489 seq_printf(m, "%s %d %s\n", n
2490 }
2491 }
2492
2493 int proc_pid_seccomp_cache(struct seq_file *m
2494 struct pid *pid, s
2495 {
2496 struct seccomp_filter *f;
2497 unsigned long flags;
2498
2499 /*
2500 * We don't want some sandboxed proce
2501 * filters consist of.
2502 */
2503 if (!file_ns_capable(m->file, &init_u
2504 return -EACCES;
2505
2506 if (!lock_task_sighand(task, &flags))
2507 return -ESRCH;
2508
2509 f = READ_ONCE(task->seccomp.filter);
2510 if (!f) {
2511 unlock_task_sighand(task, &fl
2512 return 0;
2513 }
2514
2515 /* prevent filter from being freed wh
2516 __get_seccomp_filter(f);
2517 unlock_task_sighand(task, &flags);
2518
2519 proc_pid_seccomp_cache_arch(m, SECCOM
2520 f->cache.
2521 SECCOMP_A
2522
2523 #ifdef SECCOMP_ARCH_COMPAT
2524 proc_pid_seccomp_cache_arch(m, SECCOM
2525 f->cache.
2526 SECCOMP_A
2527 #endif /* SECCOMP_ARCH_COMPAT */
2528
2529 __put_seccomp_filter(f);
2530 return 0;
2531 }
2532 #endif /* CONFIG_SECCOMP_CACHE_DEBUG */
2533
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