1 // SPDX-License-Identifier: GPL-2.0
3 * linux/kernel/seccomp.c
5 * Copyright 2004-2005 Andrea Arcangeli <andrea@cpushare.com>
7 * Copyright (C) 2012 Google, Inc.
8 * Will Drewry <wad@chromium.org>
10 * This defines a simple but solid secure-computing facility.
12 * Mode 1 uses a fixed list of allowed system calls.
13 * Mode 2 allows user-defined system call filters in the form
14 * of Berkeley Packet Filters/Linux Socket Filters.
17 #include <linux/refcount.h>
18 #include <linux/audit.h>
19 #include <linux/compat.h>
20 #include <linux/coredump.h>
21 #include <linux/kmemleak.h>
22 #include <linux/nospec.h>
23 #include <linux/prctl.h>
24 #include <linux/sched.h>
25 #include <linux/sched/task_stack.h>
26 #include <linux/seccomp.h>
27 #include <linux/slab.h>
28 #include <linux/syscalls.h>
29 #include <linux/sysctl.h>
31 #ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
32 #include <asm/syscall.h>
35 #ifdef CONFIG_SECCOMP_FILTER
36 #include <linux/file.h>
37 #include <linux/filter.h>
38 #include <linux/pid.h>
39 #include <linux/ptrace.h>
40 #include <linux/security.h>
41 #include <linux/tracehook.h>
42 #include <linux/uaccess.h>
43 #include <linux/anon_inodes.h>
44 #include <linux/lockdep.h>
49 SECCOMP_NOTIFY_REPLIED,
52 struct seccomp_knotif {
53 /* The struct pid of the task whose filter triggered the notification */
54 struct task_struct *task;
56 /* The "cookie" for this request; this is unique for this filter. */
60 * The seccomp data. This pointer is valid the entire time this
61 * notification is active, since it comes from __seccomp_filter which
62 * eclipses the entire lifecycle here.
64 const struct seccomp_data *data;
67 * Notification states. When SECCOMP_RET_USER_NOTIF is returned, a
68 * struct seccomp_knotif is created and starts out in INIT. Once the
69 * handler reads the notification off of an FD, it transitions to SENT.
70 * If a signal is received the state transitions back to INIT and
71 * another message is sent. When the userspace handler replies, state
72 * transitions to REPLIED.
74 enum notify_state state;
76 /* The return values, only valid when in SECCOMP_NOTIFY_REPLIED */
81 /* Signals when this has entered SECCOMP_NOTIFY_REPLIED */
82 struct completion ready;
84 struct list_head list;
88 * struct notification - container for seccomp userspace notifications. Since
89 * most seccomp filters will not have notification listeners attached and this
90 * structure is fairly large, we store the notification-specific stuff in a
93 * @request: A semaphore that users of this notification can wait on for
94 * changes. Actual reads and writes are still controlled with
95 * filter->notify_lock.
96 * @next_id: The id of the next request.
97 * @notifications: A list of struct seccomp_knotif elements.
100 struct semaphore request;
102 struct list_head notifications;
106 * struct seccomp_filter - container for seccomp BPF programs
108 * @refs: Reference count to manage the object lifetime.
109 * A filter's reference count is incremented for each directly
110 * attached task, once for the dependent filter, and if
111 * requested for the user notifier. When @refs reaches zero,
112 * the filter can be freed.
113 * @log: true if all actions except for SECCOMP_RET_ALLOW should be logged
114 * @prev: points to a previously installed, or inherited, filter
115 * @prog: the BPF program to evaluate
116 * @notif: the struct that holds all notification related information
117 * @notify_lock: A lock for all notification-related accesses.
118 * @wqh: A wait queue for poll if a notifier is in use.
120 * seccomp_filter objects are organized in a tree linked via the @prev
121 * pointer. For any task, it appears to be a singly-linked list starting
122 * with current->seccomp.filter, the most recently attached or inherited filter.
123 * However, multiple filters may share a @prev node, by way of fork(), which
124 * results in a unidirectional tree existing in memory. This is similar to
125 * how namespaces work.
127 * seccomp_filter objects should never be modified after being attached
128 * to a task_struct (other than @refs).
130 struct seccomp_filter {
133 struct seccomp_filter *prev;
134 struct bpf_prog *prog;
135 struct notification *notif;
136 struct mutex notify_lock;
137 wait_queue_head_t wqh;
140 /* Limit any path through the tree to 256KB worth of instructions. */
141 #define MAX_INSNS_PER_PATH ((1 << 18) / sizeof(struct sock_filter))
144 * Endianness is explicitly ignored and left for BPF program authors to manage
145 * as per the specific architecture.
147 static void populate_seccomp_data(struct seccomp_data *sd)
149 struct task_struct *task = current;
150 struct pt_regs *regs = task_pt_regs(task);
151 unsigned long args[6];
153 sd->nr = syscall_get_nr(task, regs);
154 sd->arch = syscall_get_arch(task);
155 syscall_get_arguments(task, regs, args);
156 sd->args[0] = args[0];
157 sd->args[1] = args[1];
158 sd->args[2] = args[2];
159 sd->args[3] = args[3];
160 sd->args[4] = args[4];
161 sd->args[5] = args[5];
162 sd->instruction_pointer = KSTK_EIP(task);
166 * seccomp_check_filter - verify seccomp filter code
167 * @filter: filter to verify
168 * @flen: length of filter
170 * Takes a previously checked filter (by bpf_check_classic) and
171 * redirects all filter code that loads struct sk_buff data
172 * and related data through seccomp_bpf_load. It also
173 * enforces length and alignment checking of those loads.
175 * Returns 0 if the rule set is legal or -EINVAL if not.
177 static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen)
180 for (pc = 0; pc < flen; pc++) {
181 struct sock_filter *ftest = &filter[pc];
182 u16 code = ftest->code;
186 case BPF_LD | BPF_W | BPF_ABS:
187 ftest->code = BPF_LDX | BPF_W | BPF_ABS;
188 /* 32-bit aligned and not out of bounds. */
189 if (k >= sizeof(struct seccomp_data) || k & 3)
192 case BPF_LD | BPF_W | BPF_LEN:
193 ftest->code = BPF_LD | BPF_IMM;
194 ftest->k = sizeof(struct seccomp_data);
196 case BPF_LDX | BPF_W | BPF_LEN:
197 ftest->code = BPF_LDX | BPF_IMM;
198 ftest->k = sizeof(struct seccomp_data);
200 /* Explicitly include allowed calls. */
201 case BPF_RET | BPF_K:
202 case BPF_RET | BPF_A:
203 case BPF_ALU | BPF_ADD | BPF_K:
204 case BPF_ALU | BPF_ADD | BPF_X:
205 case BPF_ALU | BPF_SUB | BPF_K:
206 case BPF_ALU | BPF_SUB | BPF_X:
207 case BPF_ALU | BPF_MUL | BPF_K:
208 case BPF_ALU | BPF_MUL | BPF_X:
209 case BPF_ALU | BPF_DIV | BPF_K:
210 case BPF_ALU | BPF_DIV | BPF_X:
211 case BPF_ALU | BPF_AND | BPF_K:
212 case BPF_ALU | BPF_AND | BPF_X:
213 case BPF_ALU | BPF_OR | BPF_K:
214 case BPF_ALU | BPF_OR | BPF_X:
215 case BPF_ALU | BPF_XOR | BPF_K:
216 case BPF_ALU | BPF_XOR | BPF_X:
217 case BPF_ALU | BPF_LSH | BPF_K:
218 case BPF_ALU | BPF_LSH | BPF_X:
219 case BPF_ALU | BPF_RSH | BPF_K:
220 case BPF_ALU | BPF_RSH | BPF_X:
221 case BPF_ALU | BPF_NEG:
222 case BPF_LD | BPF_IMM:
223 case BPF_LDX | BPF_IMM:
224 case BPF_MISC | BPF_TAX:
225 case BPF_MISC | BPF_TXA:
226 case BPF_LD | BPF_MEM:
227 case BPF_LDX | BPF_MEM:
230 case BPF_JMP | BPF_JA:
231 case BPF_JMP | BPF_JEQ | BPF_K:
232 case BPF_JMP | BPF_JEQ | BPF_X:
233 case BPF_JMP | BPF_JGE | BPF_K:
234 case BPF_JMP | BPF_JGE | BPF_X:
235 case BPF_JMP | BPF_JGT | BPF_K:
236 case BPF_JMP | BPF_JGT | BPF_X:
237 case BPF_JMP | BPF_JSET | BPF_K:
238 case BPF_JMP | BPF_JSET | BPF_X:
248 * seccomp_run_filters - evaluates all seccomp filters against @sd
249 * @sd: optional seccomp data to be passed to filters
250 * @match: stores struct seccomp_filter that resulted in the return value,
251 * unless filter returned SECCOMP_RET_ALLOW, in which case it will
254 * Returns valid seccomp BPF response codes.
256 #define ACTION_ONLY(ret) ((s32)((ret) & (SECCOMP_RET_ACTION_FULL)))
257 static u32 seccomp_run_filters(const struct seccomp_data *sd,
258 struct seccomp_filter **match)
260 u32 ret = SECCOMP_RET_ALLOW;
261 /* Make sure cross-thread synced filter points somewhere sane. */
262 struct seccomp_filter *f =
263 READ_ONCE(current->seccomp.filter);
265 /* Ensure unexpected behavior doesn't result in failing open. */
266 if (WARN_ON(f == NULL))
267 return SECCOMP_RET_KILL_PROCESS;
270 * All filters in the list are evaluated and the lowest BPF return
271 * value always takes priority (ignoring the DATA).
273 for (; f; f = f->prev) {
274 u32 cur_ret = bpf_prog_run_pin_on_cpu(f->prog, sd);
276 if (ACTION_ONLY(cur_ret) < ACTION_ONLY(ret)) {
283 #endif /* CONFIG_SECCOMP_FILTER */
285 static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode)
287 assert_spin_locked(¤t->sighand->siglock);
289 if (current->seccomp.mode && current->seccomp.mode != seccomp_mode)
295 void __weak arch_seccomp_spec_mitigate(struct task_struct *task) { }
297 static inline void seccomp_assign_mode(struct task_struct *task,
298 unsigned long seccomp_mode,
301 assert_spin_locked(&task->sighand->siglock);
303 task->seccomp.mode = seccomp_mode;
305 * Make sure TIF_SECCOMP cannot be set before the mode (and
308 smp_mb__before_atomic();
309 /* Assume default seccomp processes want spec flaw mitigation. */
310 if ((flags & SECCOMP_FILTER_FLAG_SPEC_ALLOW) == 0)
311 arch_seccomp_spec_mitigate(task);
312 set_tsk_thread_flag(task, TIF_SECCOMP);
315 #ifdef CONFIG_SECCOMP_FILTER
316 /* Returns 1 if the parent is an ancestor of the child. */
317 static int is_ancestor(struct seccomp_filter *parent,
318 struct seccomp_filter *child)
320 /* NULL is the root ancestor. */
323 for (; child; child = child->prev)
330 * seccomp_can_sync_threads: checks if all threads can be synchronized
332 * Expects sighand and cred_guard_mutex locks to be held.
334 * Returns 0 on success, -ve on error, or the pid of a thread which was
335 * either not in the correct seccomp mode or did not have an ancestral
338 static inline pid_t seccomp_can_sync_threads(void)
340 struct task_struct *thread, *caller;
342 BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
343 assert_spin_locked(¤t->sighand->siglock);
345 /* Validate all threads being eligible for synchronization. */
347 for_each_thread(caller, thread) {
350 /* Skip current, since it is initiating the sync. */
351 if (thread == caller)
354 if (thread->seccomp.mode == SECCOMP_MODE_DISABLED ||
355 (thread->seccomp.mode == SECCOMP_MODE_FILTER &&
356 is_ancestor(thread->seccomp.filter,
357 caller->seccomp.filter)))
360 /* Return the first thread that cannot be synchronized. */
361 failed = task_pid_vnr(thread);
362 /* If the pid cannot be resolved, then return -ESRCH */
363 if (WARN_ON(failed == 0))
371 static inline void seccomp_filter_free(struct seccomp_filter *filter)
374 bpf_prog_destroy(filter->prog);
379 static void __put_seccomp_filter(struct seccomp_filter *orig)
381 /* Clean up single-reference branches iteratively. */
382 while (orig && refcount_dec_and_test(&orig->refs)) {
383 struct seccomp_filter *freeme = orig;
385 seccomp_filter_free(freeme);
390 * seccomp_filter_release - Detach the task from its filter tree
391 * and drop its reference count during
394 * This function should only be called when the task is exiting as
395 * it detaches it from its filter tree. As such, READ_ONCE() and
396 * barriers are not needed here, as would normally be needed.
398 void seccomp_filter_release(struct task_struct *tsk)
400 struct seccomp_filter *orig = tsk->seccomp.filter;
402 /* Detach task from its filter tree. */
403 tsk->seccomp.filter = NULL;
404 __put_seccomp_filter(orig);
408 * seccomp_sync_threads: sets all threads to use current's filter
410 * Expects sighand and cred_guard_mutex locks to be held, and for
411 * seccomp_can_sync_threads() to have returned success already
412 * without dropping the locks.
415 static inline void seccomp_sync_threads(unsigned long flags)
417 struct task_struct *thread, *caller;
419 BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
420 assert_spin_locked(¤t->sighand->siglock);
422 /* Synchronize all threads. */
424 for_each_thread(caller, thread) {
425 /* Skip current, since it needs no changes. */
426 if (thread == caller)
429 /* Get a task reference for the new leaf node. */
430 get_seccomp_filter(caller);
432 * Drop the task reference to the shared ancestor since
433 * current's path will hold a reference. (This also
434 * allows a put before the assignment.)
436 __put_seccomp_filter(thread->seccomp.filter);
437 smp_store_release(&thread->seccomp.filter,
438 caller->seccomp.filter);
439 atomic_set(&thread->seccomp.filter_count,
440 atomic_read(&thread->seccomp.filter_count));
443 * Don't let an unprivileged task work around
444 * the no_new_privs restriction by creating
445 * a thread that sets it up, enters seccomp,
448 if (task_no_new_privs(caller))
449 task_set_no_new_privs(thread);
452 * Opt the other thread into seccomp if needed.
453 * As threads are considered to be trust-realm
454 * equivalent (see ptrace_may_access), it is safe to
455 * allow one thread to transition the other.
457 if (thread->seccomp.mode == SECCOMP_MODE_DISABLED)
458 seccomp_assign_mode(thread, SECCOMP_MODE_FILTER,
464 * seccomp_prepare_filter: Prepares a seccomp filter for use.
465 * @fprog: BPF program to install
467 * Returns filter on success or an ERR_PTR on failure.
469 static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog)
471 struct seccomp_filter *sfilter;
473 const bool save_orig = IS_ENABLED(CONFIG_CHECKPOINT_RESTORE);
475 if (fprog->len == 0 || fprog->len > BPF_MAXINSNS)
476 return ERR_PTR(-EINVAL);
478 BUG_ON(INT_MAX / fprog->len < sizeof(struct sock_filter));
481 * Installing a seccomp filter requires that the task has
482 * CAP_SYS_ADMIN in its namespace or be running with no_new_privs.
483 * This avoids scenarios where unprivileged tasks can affect the
484 * behavior of privileged children.
486 if (!task_no_new_privs(current) &&
487 security_capable(current_cred(), current_user_ns(),
488 CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) != 0)
489 return ERR_PTR(-EACCES);
491 /* Allocate a new seccomp_filter */
492 sfilter = kzalloc(sizeof(*sfilter), GFP_KERNEL | __GFP_NOWARN);
494 return ERR_PTR(-ENOMEM);
496 mutex_init(&sfilter->notify_lock);
497 ret = bpf_prog_create_from_user(&sfilter->prog, fprog,
498 seccomp_check_filter, save_orig);
504 refcount_set(&sfilter->refs, 1);
505 init_waitqueue_head(&sfilter->wqh);
511 * seccomp_prepare_user_filter - prepares a user-supplied sock_fprog
512 * @user_filter: pointer to the user data containing a sock_fprog.
514 * Returns 0 on success and non-zero otherwise.
516 static struct seccomp_filter *
517 seccomp_prepare_user_filter(const char __user *user_filter)
519 struct sock_fprog fprog;
520 struct seccomp_filter *filter = ERR_PTR(-EFAULT);
523 if (in_compat_syscall()) {
524 struct compat_sock_fprog fprog32;
525 if (copy_from_user(&fprog32, user_filter, sizeof(fprog32)))
527 fprog.len = fprog32.len;
528 fprog.filter = compat_ptr(fprog32.filter);
529 } else /* falls through to the if below. */
531 if (copy_from_user(&fprog, user_filter, sizeof(fprog)))
533 filter = seccomp_prepare_filter(&fprog);
539 * seccomp_attach_filter: validate and attach filter
540 * @flags: flags to change filter behavior
541 * @filter: seccomp filter to add to the current process
543 * Caller must be holding current->sighand->siglock lock.
545 * Returns 0 on success, -ve on error, or
546 * - in TSYNC mode: the pid of a thread which was either not in the correct
547 * seccomp mode or did not have an ancestral seccomp filter
548 * - in NEW_LISTENER mode: the fd of the new listener
550 static long seccomp_attach_filter(unsigned int flags,
551 struct seccomp_filter *filter)
553 unsigned long total_insns;
554 struct seccomp_filter *walker;
556 assert_spin_locked(¤t->sighand->siglock);
558 /* Validate resulting filter length. */
559 total_insns = filter->prog->len;
560 for (walker = current->seccomp.filter; walker; walker = walker->prev)
561 total_insns += walker->prog->len + 4; /* 4 instr penalty */
562 if (total_insns > MAX_INSNS_PER_PATH)
565 /* If thread sync has been requested, check that it is possible. */
566 if (flags & SECCOMP_FILTER_FLAG_TSYNC) {
569 ret = seccomp_can_sync_threads();
571 if (flags & SECCOMP_FILTER_FLAG_TSYNC_ESRCH)
578 /* Set log flag, if present. */
579 if (flags & SECCOMP_FILTER_FLAG_LOG)
583 * If there is an existing filter, make it the prev and don't drop its
586 filter->prev = current->seccomp.filter;
587 current->seccomp.filter = filter;
588 atomic_inc(¤t->seccomp.filter_count);
590 /* Now that the new filter is in place, synchronize to all threads. */
591 if (flags & SECCOMP_FILTER_FLAG_TSYNC)
592 seccomp_sync_threads(flags);
597 static void __get_seccomp_filter(struct seccomp_filter *filter)
599 refcount_inc(&filter->refs);
602 /* get_seccomp_filter - increments the reference count of the filter on @tsk */
603 void get_seccomp_filter(struct task_struct *tsk)
605 struct seccomp_filter *orig = tsk->seccomp.filter;
608 __get_seccomp_filter(orig);
611 static void seccomp_init_siginfo(kernel_siginfo_t *info, int syscall, int reason)
614 info->si_signo = SIGSYS;
615 info->si_code = SYS_SECCOMP;
616 info->si_call_addr = (void __user *)KSTK_EIP(current);
617 info->si_errno = reason;
618 info->si_arch = syscall_get_arch(current);
619 info->si_syscall = syscall;
623 * seccomp_send_sigsys - signals the task to allow in-process syscall emulation
624 * @syscall: syscall number to send to userland
625 * @reason: filter-supplied reason code to send to userland (via si_errno)
627 * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info.
629 static void seccomp_send_sigsys(int syscall, int reason)
631 struct kernel_siginfo info;
632 seccomp_init_siginfo(&info, syscall, reason);
633 force_sig_info(&info);
635 #endif /* CONFIG_SECCOMP_FILTER */
637 /* For use with seccomp_actions_logged */
638 #define SECCOMP_LOG_KILL_PROCESS (1 << 0)
639 #define SECCOMP_LOG_KILL_THREAD (1 << 1)
640 #define SECCOMP_LOG_TRAP (1 << 2)
641 #define SECCOMP_LOG_ERRNO (1 << 3)
642 #define SECCOMP_LOG_TRACE (1 << 4)
643 #define SECCOMP_LOG_LOG (1 << 5)
644 #define SECCOMP_LOG_ALLOW (1 << 6)
645 #define SECCOMP_LOG_USER_NOTIF (1 << 7)
647 static u32 seccomp_actions_logged = SECCOMP_LOG_KILL_PROCESS |
648 SECCOMP_LOG_KILL_THREAD |
651 SECCOMP_LOG_USER_NOTIF |
655 static inline void seccomp_log(unsigned long syscall, long signr, u32 action,
661 case SECCOMP_RET_ALLOW:
663 case SECCOMP_RET_TRAP:
664 log = requested && seccomp_actions_logged & SECCOMP_LOG_TRAP;
666 case SECCOMP_RET_ERRNO:
667 log = requested && seccomp_actions_logged & SECCOMP_LOG_ERRNO;
669 case SECCOMP_RET_TRACE:
670 log = requested && seccomp_actions_logged & SECCOMP_LOG_TRACE;
672 case SECCOMP_RET_USER_NOTIF:
673 log = requested && seccomp_actions_logged & SECCOMP_LOG_USER_NOTIF;
675 case SECCOMP_RET_LOG:
676 log = seccomp_actions_logged & SECCOMP_LOG_LOG;
678 case SECCOMP_RET_KILL_THREAD:
679 log = seccomp_actions_logged & SECCOMP_LOG_KILL_THREAD;
681 case SECCOMP_RET_KILL_PROCESS:
683 log = seccomp_actions_logged & SECCOMP_LOG_KILL_PROCESS;
687 * Emit an audit message when the action is RET_KILL_*, RET_LOG, or the
688 * FILTER_FLAG_LOG bit was set. The admin has the ability to silence
689 * any action from being logged by removing the action name from the
690 * seccomp_actions_logged sysctl.
695 audit_seccomp(syscall, signr, action);
699 * Secure computing mode 1 allows only read/write/exit/sigreturn.
700 * To be fully secure this must be combined with rlimit
701 * to limit the stack allocations too.
703 static const int mode1_syscalls[] = {
704 __NR_seccomp_read, __NR_seccomp_write, __NR_seccomp_exit, __NR_seccomp_sigreturn,
705 0, /* null terminated */
708 static void __secure_computing_strict(int this_syscall)
710 const int *syscall_whitelist = mode1_syscalls;
712 if (in_compat_syscall())
713 syscall_whitelist = get_compat_mode1_syscalls();
716 if (*syscall_whitelist == this_syscall)
718 } while (*++syscall_whitelist);
723 seccomp_log(this_syscall, SIGKILL, SECCOMP_RET_KILL_THREAD, true);
727 #ifndef CONFIG_HAVE_ARCH_SECCOMP_FILTER
728 void secure_computing_strict(int this_syscall)
730 int mode = current->seccomp.mode;
732 if (IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) &&
733 unlikely(current->ptrace & PT_SUSPEND_SECCOMP))
736 if (mode == SECCOMP_MODE_DISABLED)
738 else if (mode == SECCOMP_MODE_STRICT)
739 __secure_computing_strict(this_syscall);
745 #ifdef CONFIG_SECCOMP_FILTER
746 static u64 seccomp_next_notify_id(struct seccomp_filter *filter)
749 * Note: overflow is ok here, the id just needs to be unique per
752 lockdep_assert_held(&filter->notify_lock);
753 return filter->notif->next_id++;
756 static int seccomp_do_user_notification(int this_syscall,
757 struct seccomp_filter *match,
758 const struct seccomp_data *sd)
763 struct seccomp_knotif n = {};
765 mutex_lock(&match->notify_lock);
771 n.state = SECCOMP_NOTIFY_INIT;
773 n.id = seccomp_next_notify_id(match);
774 init_completion(&n.ready);
775 list_add(&n.list, &match->notif->notifications);
777 up(&match->notif->request);
778 wake_up_poll(&match->wqh, EPOLLIN | EPOLLRDNORM);
779 mutex_unlock(&match->notify_lock);
782 * This is where we wait for a reply from userspace.
784 err = wait_for_completion_interruptible(&n.ready);
785 mutex_lock(&match->notify_lock);
793 * Note that it's possible the listener died in between the time when
794 * we were notified of a respons (or a signal) and when we were able to
795 * re-acquire the lock, so only delete from the list if the
796 * notification actually exists.
798 * Also note that this test is only valid because there's no way to
799 * *reattach* to a notifier right now. If one is added, we'll need to
800 * keep track of the notif itself and make sure they match here.
805 mutex_unlock(&match->notify_lock);
807 /* Userspace requests to continue the syscall. */
808 if (flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE)
811 syscall_set_return_value(current, task_pt_regs(current),
816 static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
817 const bool recheck_after_trace)
819 u32 filter_ret, action;
820 struct seccomp_filter *match = NULL;
822 struct seccomp_data sd_local;
825 * Make sure that any changes to mode from another thread have
826 * been seen after TIF_SECCOMP was seen.
831 populate_seccomp_data(&sd_local);
835 filter_ret = seccomp_run_filters(sd, &match);
836 data = filter_ret & SECCOMP_RET_DATA;
837 action = filter_ret & SECCOMP_RET_ACTION_FULL;
840 case SECCOMP_RET_ERRNO:
841 /* Set low-order bits as an errno, capped at MAX_ERRNO. */
842 if (data > MAX_ERRNO)
844 syscall_set_return_value(current, task_pt_regs(current),
848 case SECCOMP_RET_TRAP:
849 /* Show the handler the original registers. */
850 syscall_rollback(current, task_pt_regs(current));
851 /* Let the filter pass back 16 bits of data. */
852 seccomp_send_sigsys(this_syscall, data);
855 case SECCOMP_RET_TRACE:
856 /* We've been put in this state by the ptracer already. */
857 if (recheck_after_trace)
860 /* ENOSYS these calls if there is no tracer attached. */
861 if (!ptrace_event_enabled(current, PTRACE_EVENT_SECCOMP)) {
862 syscall_set_return_value(current,
863 task_pt_regs(current),
868 /* Allow the BPF to provide the event message */
869 ptrace_event(PTRACE_EVENT_SECCOMP, data);
871 * The delivery of a fatal signal during event
872 * notification may silently skip tracer notification,
873 * which could leave us with a potentially unmodified
874 * syscall that the tracer would have liked to have
875 * changed. Since the process is about to die, we just
876 * force the syscall to be skipped and let the signal
877 * kill the process and correctly handle any tracer exit
880 if (fatal_signal_pending(current))
882 /* Check if the tracer forced the syscall to be skipped. */
883 this_syscall = syscall_get_nr(current, task_pt_regs(current));
884 if (this_syscall < 0)
888 * Recheck the syscall, since it may have changed. This
889 * intentionally uses a NULL struct seccomp_data to force
890 * a reload of all registers. This does not goto skip since
891 * a skip would have already been reported.
893 if (__seccomp_filter(this_syscall, NULL, true))
898 case SECCOMP_RET_USER_NOTIF:
899 if (seccomp_do_user_notification(this_syscall, match, sd))
904 case SECCOMP_RET_LOG:
905 seccomp_log(this_syscall, 0, action, true);
908 case SECCOMP_RET_ALLOW:
910 * Note that the "match" filter will always be NULL for
911 * this action since SECCOMP_RET_ALLOW is the starting
912 * state in seccomp_run_filters().
916 case SECCOMP_RET_KILL_THREAD:
917 case SECCOMP_RET_KILL_PROCESS:
919 seccomp_log(this_syscall, SIGSYS, action, true);
920 /* Dump core only if this is the last remaining thread. */
921 if (action == SECCOMP_RET_KILL_PROCESS ||
922 get_nr_threads(current) == 1) {
923 kernel_siginfo_t info;
925 /* Show the original registers in the dump. */
926 syscall_rollback(current, task_pt_regs(current));
927 /* Trigger a manual coredump since do_exit skips it. */
928 seccomp_init_siginfo(&info, this_syscall, data);
931 if (action == SECCOMP_RET_KILL_PROCESS)
932 do_group_exit(SIGSYS);
940 seccomp_log(this_syscall, 0, action, match ? match->log : false);
944 static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
945 const bool recheck_after_trace)
951 int __secure_computing(const struct seccomp_data *sd)
953 int mode = current->seccomp.mode;
956 if (IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) &&
957 unlikely(current->ptrace & PT_SUSPEND_SECCOMP))
960 this_syscall = sd ? sd->nr :
961 syscall_get_nr(current, task_pt_regs(current));
964 case SECCOMP_MODE_STRICT:
965 __secure_computing_strict(this_syscall); /* may call do_exit */
967 case SECCOMP_MODE_FILTER:
968 return __seccomp_filter(this_syscall, sd, false);
973 #endif /* CONFIG_HAVE_ARCH_SECCOMP_FILTER */
975 long prctl_get_seccomp(void)
977 return current->seccomp.mode;
981 * seccomp_set_mode_strict: internal function for setting strict seccomp
983 * Once current->seccomp.mode is non-zero, it may not be changed.
985 * Returns 0 on success or -EINVAL on failure.
987 static long seccomp_set_mode_strict(void)
989 const unsigned long seccomp_mode = SECCOMP_MODE_STRICT;
992 spin_lock_irq(¤t->sighand->siglock);
994 if (!seccomp_may_assign_mode(seccomp_mode))
1000 seccomp_assign_mode(current, seccomp_mode, 0);
1004 spin_unlock_irq(¤t->sighand->siglock);
1009 #ifdef CONFIG_SECCOMP_FILTER
1010 static int seccomp_notify_release(struct inode *inode, struct file *file)
1012 struct seccomp_filter *filter = file->private_data;
1013 struct seccomp_knotif *knotif;
1018 mutex_lock(&filter->notify_lock);
1021 * If this file is being closed because e.g. the task who owned it
1022 * died, let's wake everyone up who was waiting on us.
1024 list_for_each_entry(knotif, &filter->notif->notifications, list) {
1025 if (knotif->state == SECCOMP_NOTIFY_REPLIED)
1028 knotif->state = SECCOMP_NOTIFY_REPLIED;
1029 knotif->error = -ENOSYS;
1032 complete(&knotif->ready);
1035 kfree(filter->notif);
1036 filter->notif = NULL;
1037 mutex_unlock(&filter->notify_lock);
1038 __put_seccomp_filter(filter);
1042 /* must be called with notif_lock held */
1043 static inline struct seccomp_knotif *
1044 find_notification(struct seccomp_filter *filter, u64 id)
1046 struct seccomp_knotif *cur;
1048 lockdep_assert_held(&filter->notify_lock);
1050 list_for_each_entry(cur, &filter->notif->notifications, list) {
1059 static long seccomp_notify_recv(struct seccomp_filter *filter,
1062 struct seccomp_knotif *knotif = NULL, *cur;
1063 struct seccomp_notif unotif;
1066 /* Verify that we're not given garbage to keep struct extensible. */
1067 ret = check_zeroed_user(buf, sizeof(unotif));
1073 memset(&unotif, 0, sizeof(unotif));
1075 ret = down_interruptible(&filter->notif->request);
1079 mutex_lock(&filter->notify_lock);
1080 list_for_each_entry(cur, &filter->notif->notifications, list) {
1081 if (cur->state == SECCOMP_NOTIFY_INIT) {
1088 * If we didn't find a notification, it could be that the task was
1089 * interrupted by a fatal signal between the time we were woken and
1090 * when we were able to acquire the rw lock.
1097 unotif.id = knotif->id;
1098 unotif.pid = task_pid_vnr(knotif->task);
1099 unotif.data = *(knotif->data);
1101 knotif->state = SECCOMP_NOTIFY_SENT;
1102 wake_up_poll(&filter->wqh, EPOLLOUT | EPOLLWRNORM);
1105 mutex_unlock(&filter->notify_lock);
1107 if (ret == 0 && copy_to_user(buf, &unotif, sizeof(unotif))) {
1111 * Userspace screwed up. To make sure that we keep this
1112 * notification alive, let's reset it back to INIT. It
1113 * may have died when we released the lock, so we need to make
1114 * sure it's still around.
1116 mutex_lock(&filter->notify_lock);
1117 knotif = find_notification(filter, unotif.id);
1119 knotif->state = SECCOMP_NOTIFY_INIT;
1120 up(&filter->notif->request);
1122 mutex_unlock(&filter->notify_lock);
1128 static long seccomp_notify_send(struct seccomp_filter *filter,
1131 struct seccomp_notif_resp resp = {};
1132 struct seccomp_knotif *knotif;
1135 if (copy_from_user(&resp, buf, sizeof(resp)))
1138 if (resp.flags & ~SECCOMP_USER_NOTIF_FLAG_CONTINUE)
1141 if ((resp.flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE) &&
1142 (resp.error || resp.val))
1145 ret = mutex_lock_interruptible(&filter->notify_lock);
1149 knotif = find_notification(filter, resp.id);
1155 /* Allow exactly one reply. */
1156 if (knotif->state != SECCOMP_NOTIFY_SENT) {
1162 knotif->state = SECCOMP_NOTIFY_REPLIED;
1163 knotif->error = resp.error;
1164 knotif->val = resp.val;
1165 knotif->flags = resp.flags;
1166 complete(&knotif->ready);
1168 mutex_unlock(&filter->notify_lock);
1172 static long seccomp_notify_id_valid(struct seccomp_filter *filter,
1175 struct seccomp_knotif *knotif;
1179 if (copy_from_user(&id, buf, sizeof(id)))
1182 ret = mutex_lock_interruptible(&filter->notify_lock);
1186 knotif = find_notification(filter, id);
1187 if (knotif && knotif->state == SECCOMP_NOTIFY_SENT)
1192 mutex_unlock(&filter->notify_lock);
1196 static long seccomp_notify_ioctl(struct file *file, unsigned int cmd,
1199 struct seccomp_filter *filter = file->private_data;
1200 void __user *buf = (void __user *)arg;
1203 case SECCOMP_IOCTL_NOTIF_RECV:
1204 return seccomp_notify_recv(filter, buf);
1205 case SECCOMP_IOCTL_NOTIF_SEND:
1206 return seccomp_notify_send(filter, buf);
1207 case SECCOMP_IOCTL_NOTIF_ID_VALID:
1208 return seccomp_notify_id_valid(filter, buf);
1214 static __poll_t seccomp_notify_poll(struct file *file,
1215 struct poll_table_struct *poll_tab)
1217 struct seccomp_filter *filter = file->private_data;
1219 struct seccomp_knotif *cur;
1221 poll_wait(file, &filter->wqh, poll_tab);
1223 if (mutex_lock_interruptible(&filter->notify_lock) < 0)
1226 list_for_each_entry(cur, &filter->notif->notifications, list) {
1227 if (cur->state == SECCOMP_NOTIFY_INIT)
1228 ret |= EPOLLIN | EPOLLRDNORM;
1229 if (cur->state == SECCOMP_NOTIFY_SENT)
1230 ret |= EPOLLOUT | EPOLLWRNORM;
1231 if ((ret & EPOLLIN) && (ret & EPOLLOUT))
1235 mutex_unlock(&filter->notify_lock);
1240 static const struct file_operations seccomp_notify_ops = {
1241 .poll = seccomp_notify_poll,
1242 .release = seccomp_notify_release,
1243 .unlocked_ioctl = seccomp_notify_ioctl,
1244 .compat_ioctl = seccomp_notify_ioctl,
1247 static struct file *init_listener(struct seccomp_filter *filter)
1249 struct file *ret = ERR_PTR(-EBUSY);
1250 struct seccomp_filter *cur;
1252 for (cur = current->seccomp.filter; cur; cur = cur->prev) {
1257 ret = ERR_PTR(-ENOMEM);
1258 filter->notif = kzalloc(sizeof(*(filter->notif)), GFP_KERNEL);
1262 sema_init(&filter->notif->request, 0);
1263 filter->notif->next_id = get_random_u64();
1264 INIT_LIST_HEAD(&filter->notif->notifications);
1266 ret = anon_inode_getfile("seccomp notify", &seccomp_notify_ops,
1271 /* The file has a reference to it now */
1272 __get_seccomp_filter(filter);
1276 kfree(filter->notif);
1282 * seccomp_set_mode_filter: internal function for setting seccomp filter
1283 * @flags: flags to change filter behavior
1284 * @filter: struct sock_fprog containing filter
1286 * This function may be called repeatedly to install additional filters.
1287 * Every filter successfully installed will be evaluated (in reverse order)
1288 * for each system call the task makes.
1290 * Once current->seccomp.mode is non-zero, it may not be changed.
1292 * Returns 0 on success or -EINVAL on failure.
1294 static long seccomp_set_mode_filter(unsigned int flags,
1295 const char __user *filter)
1297 const unsigned long seccomp_mode = SECCOMP_MODE_FILTER;
1298 struct seccomp_filter *prepared = NULL;
1301 struct file *listener_f = NULL;
1303 /* Validate flags. */
1304 if (flags & ~SECCOMP_FILTER_FLAG_MASK)
1308 * In the successful case, NEW_LISTENER returns the new listener fd.
1309 * But in the failure case, TSYNC returns the thread that died. If you
1310 * combine these two flags, there's no way to tell whether something
1311 * succeeded or failed. So, let's disallow this combination if the user
1312 * has not explicitly requested no errors from TSYNC.
1314 if ((flags & SECCOMP_FILTER_FLAG_TSYNC) &&
1315 (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) &&
1316 ((flags & SECCOMP_FILTER_FLAG_TSYNC_ESRCH) == 0))
1319 /* Prepare the new filter before holding any locks. */
1320 prepared = seccomp_prepare_user_filter(filter);
1321 if (IS_ERR(prepared))
1322 return PTR_ERR(prepared);
1324 if (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) {
1325 listener = get_unused_fd_flags(O_CLOEXEC);
1331 listener_f = init_listener(prepared);
1332 if (IS_ERR(listener_f)) {
1333 put_unused_fd(listener);
1334 ret = PTR_ERR(listener_f);
1340 * Make sure we cannot change seccomp or nnp state via TSYNC
1341 * while another thread is in the middle of calling exec.
1343 if (flags & SECCOMP_FILTER_FLAG_TSYNC &&
1344 mutex_lock_killable(¤t->signal->cred_guard_mutex))
1347 spin_lock_irq(¤t->sighand->siglock);
1349 if (!seccomp_may_assign_mode(seccomp_mode))
1352 ret = seccomp_attach_filter(flags, prepared);
1355 /* Do not free the successfully attached filter. */
1358 seccomp_assign_mode(current, seccomp_mode, flags);
1360 spin_unlock_irq(¤t->sighand->siglock);
1361 if (flags & SECCOMP_FILTER_FLAG_TSYNC)
1362 mutex_unlock(¤t->signal->cred_guard_mutex);
1364 if (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) {
1366 listener_f->private_data = NULL;
1368 put_unused_fd(listener);
1370 fd_install(listener, listener_f);
1375 seccomp_filter_free(prepared);
1379 static inline long seccomp_set_mode_filter(unsigned int flags,
1380 const char __user *filter)
1386 static long seccomp_get_action_avail(const char __user *uaction)
1390 if (copy_from_user(&action, uaction, sizeof(action)))
1394 case SECCOMP_RET_KILL_PROCESS:
1395 case SECCOMP_RET_KILL_THREAD:
1396 case SECCOMP_RET_TRAP:
1397 case SECCOMP_RET_ERRNO:
1398 case SECCOMP_RET_USER_NOTIF:
1399 case SECCOMP_RET_TRACE:
1400 case SECCOMP_RET_LOG:
1401 case SECCOMP_RET_ALLOW:
1410 static long seccomp_get_notif_sizes(void __user *usizes)
1412 struct seccomp_notif_sizes sizes = {
1413 .seccomp_notif = sizeof(struct seccomp_notif),
1414 .seccomp_notif_resp = sizeof(struct seccomp_notif_resp),
1415 .seccomp_data = sizeof(struct seccomp_data),
1418 if (copy_to_user(usizes, &sizes, sizeof(sizes)))
1424 /* Common entry point for both prctl and syscall. */
1425 static long do_seccomp(unsigned int op, unsigned int flags,
1429 case SECCOMP_SET_MODE_STRICT:
1430 if (flags != 0 || uargs != NULL)
1432 return seccomp_set_mode_strict();
1433 case SECCOMP_SET_MODE_FILTER:
1434 return seccomp_set_mode_filter(flags, uargs);
1435 case SECCOMP_GET_ACTION_AVAIL:
1439 return seccomp_get_action_avail(uargs);
1440 case SECCOMP_GET_NOTIF_SIZES:
1444 return seccomp_get_notif_sizes(uargs);
1450 SYSCALL_DEFINE3(seccomp, unsigned int, op, unsigned int, flags,
1451 void __user *, uargs)
1453 return do_seccomp(op, flags, uargs);
1457 * prctl_set_seccomp: configures current->seccomp.mode
1458 * @seccomp_mode: requested mode to use
1459 * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER
1461 * Returns 0 on success or -EINVAL on failure.
1463 long prctl_set_seccomp(unsigned long seccomp_mode, void __user *filter)
1468 switch (seccomp_mode) {
1469 case SECCOMP_MODE_STRICT:
1470 op = SECCOMP_SET_MODE_STRICT;
1472 * Setting strict mode through prctl always ignored filter,
1473 * so make sure it is always NULL here to pass the internal
1474 * check in do_seccomp().
1478 case SECCOMP_MODE_FILTER:
1479 op = SECCOMP_SET_MODE_FILTER;
1486 /* prctl interface doesn't have flags, so they are always zero. */
1487 return do_seccomp(op, 0, uargs);
1490 #if defined(CONFIG_SECCOMP_FILTER) && defined(CONFIG_CHECKPOINT_RESTORE)
1491 static struct seccomp_filter *get_nth_filter(struct task_struct *task,
1492 unsigned long filter_off)
1494 struct seccomp_filter *orig, *filter;
1495 unsigned long count;
1498 * Note: this is only correct because the caller should be the (ptrace)
1499 * tracer of the task, otherwise lock_task_sighand is needed.
1501 spin_lock_irq(&task->sighand->siglock);
1503 if (task->seccomp.mode != SECCOMP_MODE_FILTER) {
1504 spin_unlock_irq(&task->sighand->siglock);
1505 return ERR_PTR(-EINVAL);
1508 orig = task->seccomp.filter;
1509 __get_seccomp_filter(orig);
1510 spin_unlock_irq(&task->sighand->siglock);
1513 for (filter = orig; filter; filter = filter->prev)
1516 if (filter_off >= count) {
1517 filter = ERR_PTR(-ENOENT);
1521 count -= filter_off;
1522 for (filter = orig; filter && count > 1; filter = filter->prev)
1525 if (WARN_ON(count != 1 || !filter)) {
1526 filter = ERR_PTR(-ENOENT);
1530 __get_seccomp_filter(filter);
1533 __put_seccomp_filter(orig);
1537 long seccomp_get_filter(struct task_struct *task, unsigned long filter_off,
1540 struct seccomp_filter *filter;
1541 struct sock_fprog_kern *fprog;
1544 if (!capable(CAP_SYS_ADMIN) ||
1545 current->seccomp.mode != SECCOMP_MODE_DISABLED) {
1549 filter = get_nth_filter(task, filter_off);
1551 return PTR_ERR(filter);
1553 fprog = filter->prog->orig_prog;
1555 /* This must be a new non-cBPF filter, since we save
1556 * every cBPF filter's orig_prog above when
1557 * CONFIG_CHECKPOINT_RESTORE is enabled.
1567 if (copy_to_user(data, fprog->filter, bpf_classic_proglen(fprog)))
1571 __put_seccomp_filter(filter);
1575 long seccomp_get_metadata(struct task_struct *task,
1576 unsigned long size, void __user *data)
1579 struct seccomp_filter *filter;
1580 struct seccomp_metadata kmd = {};
1582 if (!capable(CAP_SYS_ADMIN) ||
1583 current->seccomp.mode != SECCOMP_MODE_DISABLED) {
1587 size = min_t(unsigned long, size, sizeof(kmd));
1589 if (size < sizeof(kmd.filter_off))
1592 if (copy_from_user(&kmd.filter_off, data, sizeof(kmd.filter_off)))
1595 filter = get_nth_filter(task, kmd.filter_off);
1597 return PTR_ERR(filter);
1600 kmd.flags |= SECCOMP_FILTER_FLAG_LOG;
1603 if (copy_to_user(data, &kmd, size))
1606 __put_seccomp_filter(filter);
1611 #ifdef CONFIG_SYSCTL
1613 /* Human readable action names for friendly sysctl interaction */
1614 #define SECCOMP_RET_KILL_PROCESS_NAME "kill_process"
1615 #define SECCOMP_RET_KILL_THREAD_NAME "kill_thread"
1616 #define SECCOMP_RET_TRAP_NAME "trap"
1617 #define SECCOMP_RET_ERRNO_NAME "errno"
1618 #define SECCOMP_RET_USER_NOTIF_NAME "user_notif"
1619 #define SECCOMP_RET_TRACE_NAME "trace"
1620 #define SECCOMP_RET_LOG_NAME "log"
1621 #define SECCOMP_RET_ALLOW_NAME "allow"
1623 static const char seccomp_actions_avail[] =
1624 SECCOMP_RET_KILL_PROCESS_NAME " "
1625 SECCOMP_RET_KILL_THREAD_NAME " "
1626 SECCOMP_RET_TRAP_NAME " "
1627 SECCOMP_RET_ERRNO_NAME " "
1628 SECCOMP_RET_USER_NOTIF_NAME " "
1629 SECCOMP_RET_TRACE_NAME " "
1630 SECCOMP_RET_LOG_NAME " "
1631 SECCOMP_RET_ALLOW_NAME;
1633 struct seccomp_log_name {
1638 static const struct seccomp_log_name seccomp_log_names[] = {
1639 { SECCOMP_LOG_KILL_PROCESS, SECCOMP_RET_KILL_PROCESS_NAME },
1640 { SECCOMP_LOG_KILL_THREAD, SECCOMP_RET_KILL_THREAD_NAME },
1641 { SECCOMP_LOG_TRAP, SECCOMP_RET_TRAP_NAME },
1642 { SECCOMP_LOG_ERRNO, SECCOMP_RET_ERRNO_NAME },
1643 { SECCOMP_LOG_USER_NOTIF, SECCOMP_RET_USER_NOTIF_NAME },
1644 { SECCOMP_LOG_TRACE, SECCOMP_RET_TRACE_NAME },
1645 { SECCOMP_LOG_LOG, SECCOMP_RET_LOG_NAME },
1646 { SECCOMP_LOG_ALLOW, SECCOMP_RET_ALLOW_NAME },
1650 static bool seccomp_names_from_actions_logged(char *names, size_t size,
1654 const struct seccomp_log_name *cur;
1655 bool append_sep = false;
1657 for (cur = seccomp_log_names; cur->name && size; cur++) {
1660 if (!(actions_logged & cur->log))
1664 ret = strscpy(names, sep, size);
1673 ret = strscpy(names, cur->name, size);
1684 static bool seccomp_action_logged_from_name(u32 *action_logged,
1687 const struct seccomp_log_name *cur;
1689 for (cur = seccomp_log_names; cur->name; cur++) {
1690 if (!strcmp(cur->name, name)) {
1691 *action_logged = cur->log;
1699 static bool seccomp_actions_logged_from_names(u32 *actions_logged, char *names)
1703 *actions_logged = 0;
1704 while ((name = strsep(&names, " ")) && *name) {
1705 u32 action_logged = 0;
1707 if (!seccomp_action_logged_from_name(&action_logged, name))
1710 *actions_logged |= action_logged;
1716 static int read_actions_logged(struct ctl_table *ro_table, void __user *buffer,
1717 size_t *lenp, loff_t *ppos)
1719 char names[sizeof(seccomp_actions_avail)];
1720 struct ctl_table table;
1722 memset(names, 0, sizeof(names));
1724 if (!seccomp_names_from_actions_logged(names, sizeof(names),
1725 seccomp_actions_logged, " "))
1730 table.maxlen = sizeof(names);
1731 return proc_dostring(&table, 0, buffer, lenp, ppos);
1734 static int write_actions_logged(struct ctl_table *ro_table, void __user *buffer,
1735 size_t *lenp, loff_t *ppos, u32 *actions_logged)
1737 char names[sizeof(seccomp_actions_avail)];
1738 struct ctl_table table;
1741 if (!capable(CAP_SYS_ADMIN))
1744 memset(names, 0, sizeof(names));
1748 table.maxlen = sizeof(names);
1749 ret = proc_dostring(&table, 1, buffer, lenp, ppos);
1753 if (!seccomp_actions_logged_from_names(actions_logged, table.data))
1756 if (*actions_logged & SECCOMP_LOG_ALLOW)
1759 seccomp_actions_logged = *actions_logged;
1763 static void audit_actions_logged(u32 actions_logged, u32 old_actions_logged,
1766 char names[sizeof(seccomp_actions_avail)];
1767 char old_names[sizeof(seccomp_actions_avail)];
1768 const char *new = names;
1769 const char *old = old_names;
1774 memset(names, 0, sizeof(names));
1775 memset(old_names, 0, sizeof(old_names));
1779 else if (!actions_logged)
1781 else if (!seccomp_names_from_actions_logged(names, sizeof(names),
1782 actions_logged, ","))
1785 if (!old_actions_logged)
1787 else if (!seccomp_names_from_actions_logged(old_names,
1789 old_actions_logged, ","))
1792 return audit_seccomp_actions_logged(new, old, !ret);
1795 static int seccomp_actions_logged_handler(struct ctl_table *ro_table, int write,
1796 void *buffer, size_t *lenp,
1802 u32 actions_logged = 0;
1803 u32 old_actions_logged = seccomp_actions_logged;
1805 ret = write_actions_logged(ro_table, buffer, lenp, ppos,
1807 audit_actions_logged(actions_logged, old_actions_logged, ret);
1809 ret = read_actions_logged(ro_table, buffer, lenp, ppos);
1814 static struct ctl_path seccomp_sysctl_path[] = {
1815 { .procname = "kernel", },
1816 { .procname = "seccomp", },
1820 static struct ctl_table seccomp_sysctl_table[] = {
1822 .procname = "actions_avail",
1823 .data = (void *) &seccomp_actions_avail,
1824 .maxlen = sizeof(seccomp_actions_avail),
1826 .proc_handler = proc_dostring,
1829 .procname = "actions_logged",
1831 .proc_handler = seccomp_actions_logged_handler,
1836 static int __init seccomp_sysctl_init(void)
1838 struct ctl_table_header *hdr;
1840 hdr = register_sysctl_paths(seccomp_sysctl_path, seccomp_sysctl_table);
1842 pr_warn("seccomp: sysctl registration failed\n");
1844 kmemleak_not_leak(hdr);
1849 device_initcall(seccomp_sysctl_init)
1851 #endif /* CONFIG_SYSCTL */