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>
48 SECCOMP_NOTIFY_REPLIED,
51 struct seccomp_knotif {
52 /* The struct pid of the task whose filter triggered the notification */
53 struct task_struct *task;
55 /* The "cookie" for this request; this is unique for this filter. */
59 * The seccomp data. This pointer is valid the entire time this
60 * notification is active, since it comes from __seccomp_filter which
61 * eclipses the entire lifecycle here.
63 const struct seccomp_data *data;
66 * Notification states. When SECCOMP_RET_USER_NOTIF is returned, a
67 * struct seccomp_knotif is created and starts out in INIT. Once the
68 * handler reads the notification off of an FD, it transitions to SENT.
69 * If a signal is received the state transitions back to INIT and
70 * another message is sent. When the userspace handler replies, state
71 * transitions to REPLIED.
73 enum notify_state state;
75 /* The return values, only valid when in SECCOMP_NOTIFY_REPLIED */
80 /* Signals when this has entered SECCOMP_NOTIFY_REPLIED */
81 struct completion ready;
83 struct list_head list;
87 * struct notification - container for seccomp userspace notifications. Since
88 * most seccomp filters will not have notification listeners attached and this
89 * structure is fairly large, we store the notification-specific stuff in a
92 * @request: A semaphore that users of this notification can wait on for
93 * changes. Actual reads and writes are still controlled with
94 * filter->notify_lock.
95 * @next_id: The id of the next request.
96 * @notifications: A list of struct seccomp_knotif elements.
97 * @wqh: A wait queue for poll.
100 struct semaphore request;
102 struct list_head notifications;
103 wait_queue_head_t wqh;
107 * struct seccomp_filter - container for seccomp BPF programs
109 * @usage: reference count to manage the object lifetime.
110 * get/put helpers should be used when accessing an instance
111 * outside of a lifetime-guarded section. In general, this
112 * is only needed for handling filters shared across tasks.
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.
119 * seccomp_filter objects are organized in a tree linked via the @prev
120 * pointer. For any task, it appears to be a singly-linked list starting
121 * with current->seccomp.filter, the most recently attached or inherited filter.
122 * However, multiple filters may share a @prev node, by way of fork(), which
123 * results in a unidirectional tree existing in memory. This is similar to
124 * how namespaces work.
126 * seccomp_filter objects should never be modified after being attached
127 * to a task_struct (other than @usage).
129 struct seccomp_filter {
132 struct seccomp_filter *prev;
133 struct bpf_prog *prog;
134 struct notification *notif;
135 struct mutex notify_lock;
138 /* Limit any path through the tree to 256KB worth of instructions. */
139 #define MAX_INSNS_PER_PATH ((1 << 18) / sizeof(struct sock_filter))
142 * Endianness is explicitly ignored and left for BPF program authors to manage
143 * as per the specific architecture.
145 static void populate_seccomp_data(struct seccomp_data *sd)
147 struct task_struct *task = current;
148 struct pt_regs *regs = task_pt_regs(task);
149 unsigned long args[6];
151 sd->nr = syscall_get_nr(task, regs);
152 sd->arch = syscall_get_arch(task);
153 syscall_get_arguments(task, regs, args);
154 sd->args[0] = args[0];
155 sd->args[1] = args[1];
156 sd->args[2] = args[2];
157 sd->args[3] = args[3];
158 sd->args[4] = args[4];
159 sd->args[5] = args[5];
160 sd->instruction_pointer = KSTK_EIP(task);
164 * seccomp_check_filter - verify seccomp filter code
165 * @filter: filter to verify
166 * @flen: length of filter
168 * Takes a previously checked filter (by bpf_check_classic) and
169 * redirects all filter code that loads struct sk_buff data
170 * and related data through seccomp_bpf_load. It also
171 * enforces length and alignment checking of those loads.
173 * Returns 0 if the rule set is legal or -EINVAL if not.
175 static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen)
178 for (pc = 0; pc < flen; pc++) {
179 struct sock_filter *ftest = &filter[pc];
180 u16 code = ftest->code;
184 case BPF_LD | BPF_W | BPF_ABS:
185 ftest->code = BPF_LDX | BPF_W | BPF_ABS;
186 /* 32-bit aligned and not out of bounds. */
187 if (k >= sizeof(struct seccomp_data) || k & 3)
190 case BPF_LD | BPF_W | BPF_LEN:
191 ftest->code = BPF_LD | BPF_IMM;
192 ftest->k = sizeof(struct seccomp_data);
194 case BPF_LDX | BPF_W | BPF_LEN:
195 ftest->code = BPF_LDX | BPF_IMM;
196 ftest->k = sizeof(struct seccomp_data);
198 /* Explicitly include allowed calls. */
199 case BPF_RET | BPF_K:
200 case BPF_RET | BPF_A:
201 case BPF_ALU | BPF_ADD | BPF_K:
202 case BPF_ALU | BPF_ADD | BPF_X:
203 case BPF_ALU | BPF_SUB | BPF_K:
204 case BPF_ALU | BPF_SUB | BPF_X:
205 case BPF_ALU | BPF_MUL | BPF_K:
206 case BPF_ALU | BPF_MUL | BPF_X:
207 case BPF_ALU | BPF_DIV | BPF_K:
208 case BPF_ALU | BPF_DIV | BPF_X:
209 case BPF_ALU | BPF_AND | BPF_K:
210 case BPF_ALU | BPF_AND | BPF_X:
211 case BPF_ALU | BPF_OR | BPF_K:
212 case BPF_ALU | BPF_OR | BPF_X:
213 case BPF_ALU | BPF_XOR | BPF_K:
214 case BPF_ALU | BPF_XOR | BPF_X:
215 case BPF_ALU | BPF_LSH | BPF_K:
216 case BPF_ALU | BPF_LSH | BPF_X:
217 case BPF_ALU | BPF_RSH | BPF_K:
218 case BPF_ALU | BPF_RSH | BPF_X:
219 case BPF_ALU | BPF_NEG:
220 case BPF_LD | BPF_IMM:
221 case BPF_LDX | BPF_IMM:
222 case BPF_MISC | BPF_TAX:
223 case BPF_MISC | BPF_TXA:
224 case BPF_LD | BPF_MEM:
225 case BPF_LDX | BPF_MEM:
228 case BPF_JMP | BPF_JA:
229 case BPF_JMP | BPF_JEQ | BPF_K:
230 case BPF_JMP | BPF_JEQ | BPF_X:
231 case BPF_JMP | BPF_JGE | BPF_K:
232 case BPF_JMP | BPF_JGE | BPF_X:
233 case BPF_JMP | BPF_JGT | BPF_K:
234 case BPF_JMP | BPF_JGT | BPF_X:
235 case BPF_JMP | BPF_JSET | BPF_K:
236 case BPF_JMP | BPF_JSET | BPF_X:
246 * seccomp_run_filters - evaluates all seccomp filters against @sd
247 * @sd: optional seccomp data to be passed to filters
248 * @match: stores struct seccomp_filter that resulted in the return value,
249 * unless filter returned SECCOMP_RET_ALLOW, in which case it will
252 * Returns valid seccomp BPF response codes.
254 #define ACTION_ONLY(ret) ((s32)((ret) & (SECCOMP_RET_ACTION_FULL)))
255 static u32 seccomp_run_filters(const struct seccomp_data *sd,
256 struct seccomp_filter **match)
258 u32 ret = SECCOMP_RET_ALLOW;
259 /* Make sure cross-thread synced filter points somewhere sane. */
260 struct seccomp_filter *f =
261 READ_ONCE(current->seccomp.filter);
263 /* Ensure unexpected behavior doesn't result in failing open. */
264 if (WARN_ON(f == NULL))
265 return SECCOMP_RET_KILL_PROCESS;
268 * All filters in the list are evaluated and the lowest BPF return
269 * value always takes priority (ignoring the DATA).
272 for (; f; f = f->prev) {
273 u32 cur_ret = BPF_PROG_RUN(f->prog, sd);
275 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))
372 * seccomp_sync_threads: sets all threads to use current's filter
374 * Expects sighand and cred_guard_mutex locks to be held, and for
375 * seccomp_can_sync_threads() to have returned success already
376 * without dropping the locks.
379 static inline void seccomp_sync_threads(unsigned long flags)
381 struct task_struct *thread, *caller;
383 BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex));
384 assert_spin_locked(¤t->sighand->siglock);
386 /* Synchronize all threads. */
388 for_each_thread(caller, thread) {
389 /* Skip current, since it needs no changes. */
390 if (thread == caller)
393 /* Get a task reference for the new leaf node. */
394 get_seccomp_filter(caller);
396 * Drop the task reference to the shared ancestor since
397 * current's path will hold a reference. (This also
398 * allows a put before the assignment.)
400 put_seccomp_filter(thread);
401 smp_store_release(&thread->seccomp.filter,
402 caller->seccomp.filter);
405 * Don't let an unprivileged task work around
406 * the no_new_privs restriction by creating
407 * a thread that sets it up, enters seccomp,
410 if (task_no_new_privs(caller))
411 task_set_no_new_privs(thread);
414 * Opt the other thread into seccomp if needed.
415 * As threads are considered to be trust-realm
416 * equivalent (see ptrace_may_access), it is safe to
417 * allow one thread to transition the other.
419 if (thread->seccomp.mode == SECCOMP_MODE_DISABLED)
420 seccomp_assign_mode(thread, SECCOMP_MODE_FILTER,
426 * seccomp_prepare_filter: Prepares a seccomp filter for use.
427 * @fprog: BPF program to install
429 * Returns filter on success or an ERR_PTR on failure.
431 static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog)
433 struct seccomp_filter *sfilter;
435 const bool save_orig = IS_ENABLED(CONFIG_CHECKPOINT_RESTORE);
437 if (fprog->len == 0 || fprog->len > BPF_MAXINSNS)
438 return ERR_PTR(-EINVAL);
440 BUG_ON(INT_MAX / fprog->len < sizeof(struct sock_filter));
443 * Installing a seccomp filter requires that the task has
444 * CAP_SYS_ADMIN in its namespace or be running with no_new_privs.
445 * This avoids scenarios where unprivileged tasks can affect the
446 * behavior of privileged children.
448 if (!task_no_new_privs(current) &&
449 security_capable(current_cred(), current_user_ns(),
450 CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) != 0)
451 return ERR_PTR(-EACCES);
453 /* Allocate a new seccomp_filter */
454 sfilter = kzalloc(sizeof(*sfilter), GFP_KERNEL | __GFP_NOWARN);
456 return ERR_PTR(-ENOMEM);
458 mutex_init(&sfilter->notify_lock);
459 ret = bpf_prog_create_from_user(&sfilter->prog, fprog,
460 seccomp_check_filter, save_orig);
466 refcount_set(&sfilter->usage, 1);
472 * seccomp_prepare_user_filter - prepares a user-supplied sock_fprog
473 * @user_filter: pointer to the user data containing a sock_fprog.
475 * Returns 0 on success and non-zero otherwise.
477 static struct seccomp_filter *
478 seccomp_prepare_user_filter(const char __user *user_filter)
480 struct sock_fprog fprog;
481 struct seccomp_filter *filter = ERR_PTR(-EFAULT);
484 if (in_compat_syscall()) {
485 struct compat_sock_fprog fprog32;
486 if (copy_from_user(&fprog32, user_filter, sizeof(fprog32)))
488 fprog.len = fprog32.len;
489 fprog.filter = compat_ptr(fprog32.filter);
490 } else /* falls through to the if below. */
492 if (copy_from_user(&fprog, user_filter, sizeof(fprog)))
494 filter = seccomp_prepare_filter(&fprog);
500 * seccomp_attach_filter: validate and attach filter
501 * @flags: flags to change filter behavior
502 * @filter: seccomp filter to add to the current process
504 * Caller must be holding current->sighand->siglock lock.
506 * Returns 0 on success, -ve on error, or
507 * - in TSYNC mode: the pid of a thread which was either not in the correct
508 * seccomp mode or did not have an ancestral seccomp filter
509 * - in NEW_LISTENER mode: the fd of the new listener
511 static long seccomp_attach_filter(unsigned int flags,
512 struct seccomp_filter *filter)
514 unsigned long total_insns;
515 struct seccomp_filter *walker;
517 assert_spin_locked(¤t->sighand->siglock);
519 /* Validate resulting filter length. */
520 total_insns = filter->prog->len;
521 for (walker = current->seccomp.filter; walker; walker = walker->prev)
522 total_insns += walker->prog->len + 4; /* 4 instr penalty */
523 if (total_insns > MAX_INSNS_PER_PATH)
526 /* If thread sync has been requested, check that it is possible. */
527 if (flags & SECCOMP_FILTER_FLAG_TSYNC) {
530 ret = seccomp_can_sync_threads();
532 if (flags & SECCOMP_FILTER_FLAG_TSYNC_ESRCH)
539 /* Set log flag, if present. */
540 if (flags & SECCOMP_FILTER_FLAG_LOG)
544 * If there is an existing filter, make it the prev and don't drop its
547 filter->prev = current->seccomp.filter;
548 current->seccomp.filter = filter;
550 /* Now that the new filter is in place, synchronize to all threads. */
551 if (flags & SECCOMP_FILTER_FLAG_TSYNC)
552 seccomp_sync_threads(flags);
557 static void __get_seccomp_filter(struct seccomp_filter *filter)
559 refcount_inc(&filter->usage);
562 /* get_seccomp_filter - increments the reference count of the filter on @tsk */
563 void get_seccomp_filter(struct task_struct *tsk)
565 struct seccomp_filter *orig = tsk->seccomp.filter;
568 __get_seccomp_filter(orig);
571 static inline void seccomp_filter_free(struct seccomp_filter *filter)
574 bpf_prog_destroy(filter->prog);
579 static void __put_seccomp_filter(struct seccomp_filter *orig)
581 /* Clean up single-reference branches iteratively. */
582 while (orig && refcount_dec_and_test(&orig->usage)) {
583 struct seccomp_filter *freeme = orig;
585 seccomp_filter_free(freeme);
589 /* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */
590 void put_seccomp_filter(struct task_struct *tsk)
592 __put_seccomp_filter(tsk->seccomp.filter);
595 static void seccomp_init_siginfo(kernel_siginfo_t *info, int syscall, int reason)
598 info->si_signo = SIGSYS;
599 info->si_code = SYS_SECCOMP;
600 info->si_call_addr = (void __user *)KSTK_EIP(current);
601 info->si_errno = reason;
602 info->si_arch = syscall_get_arch(current);
603 info->si_syscall = syscall;
607 * seccomp_send_sigsys - signals the task to allow in-process syscall emulation
608 * @syscall: syscall number to send to userland
609 * @reason: filter-supplied reason code to send to userland (via si_errno)
611 * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info.
613 static void seccomp_send_sigsys(int syscall, int reason)
615 struct kernel_siginfo info;
616 seccomp_init_siginfo(&info, syscall, reason);
617 force_sig_info(&info);
619 #endif /* CONFIG_SECCOMP_FILTER */
621 /* For use with seccomp_actions_logged */
622 #define SECCOMP_LOG_KILL_PROCESS (1 << 0)
623 #define SECCOMP_LOG_KILL_THREAD (1 << 1)
624 #define SECCOMP_LOG_TRAP (1 << 2)
625 #define SECCOMP_LOG_ERRNO (1 << 3)
626 #define SECCOMP_LOG_TRACE (1 << 4)
627 #define SECCOMP_LOG_LOG (1 << 5)
628 #define SECCOMP_LOG_ALLOW (1 << 6)
629 #define SECCOMP_LOG_USER_NOTIF (1 << 7)
631 static u32 seccomp_actions_logged = SECCOMP_LOG_KILL_PROCESS |
632 SECCOMP_LOG_KILL_THREAD |
635 SECCOMP_LOG_USER_NOTIF |
639 static inline void seccomp_log(unsigned long syscall, long signr, u32 action,
645 case SECCOMP_RET_ALLOW:
647 case SECCOMP_RET_TRAP:
648 log = requested && seccomp_actions_logged & SECCOMP_LOG_TRAP;
650 case SECCOMP_RET_ERRNO:
651 log = requested && seccomp_actions_logged & SECCOMP_LOG_ERRNO;
653 case SECCOMP_RET_TRACE:
654 log = requested && seccomp_actions_logged & SECCOMP_LOG_TRACE;
656 case SECCOMP_RET_USER_NOTIF:
657 log = requested && seccomp_actions_logged & SECCOMP_LOG_USER_NOTIF;
659 case SECCOMP_RET_LOG:
660 log = seccomp_actions_logged & SECCOMP_LOG_LOG;
662 case SECCOMP_RET_KILL_THREAD:
663 log = seccomp_actions_logged & SECCOMP_LOG_KILL_THREAD;
665 case SECCOMP_RET_KILL_PROCESS:
667 log = seccomp_actions_logged & SECCOMP_LOG_KILL_PROCESS;
671 * Emit an audit message when the action is RET_KILL_*, RET_LOG, or the
672 * FILTER_FLAG_LOG bit was set. The admin has the ability to silence
673 * any action from being logged by removing the action name from the
674 * seccomp_actions_logged sysctl.
679 audit_seccomp(syscall, signr, action);
683 * Secure computing mode 1 allows only read/write/exit/sigreturn.
684 * To be fully secure this must be combined with rlimit
685 * to limit the stack allocations too.
687 static const int mode1_syscalls[] = {
688 __NR_seccomp_read, __NR_seccomp_write, __NR_seccomp_exit, __NR_seccomp_sigreturn,
689 0, /* null terminated */
692 static void __secure_computing_strict(int this_syscall)
694 const int *syscall_whitelist = mode1_syscalls;
696 if (in_compat_syscall())
697 syscall_whitelist = get_compat_mode1_syscalls();
700 if (*syscall_whitelist == this_syscall)
702 } while (*++syscall_whitelist);
707 seccomp_log(this_syscall, SIGKILL, SECCOMP_RET_KILL_THREAD, true);
711 #ifndef CONFIG_HAVE_ARCH_SECCOMP_FILTER
712 void secure_computing_strict(int this_syscall)
714 int mode = current->seccomp.mode;
716 if (IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) &&
717 unlikely(current->ptrace & PT_SUSPEND_SECCOMP))
720 if (mode == SECCOMP_MODE_DISABLED)
722 else if (mode == SECCOMP_MODE_STRICT)
723 __secure_computing_strict(this_syscall);
729 #ifdef CONFIG_SECCOMP_FILTER
730 static u64 seccomp_next_notify_id(struct seccomp_filter *filter)
733 * Note: overflow is ok here, the id just needs to be unique per
736 lockdep_assert_held(&filter->notify_lock);
737 return filter->notif->next_id++;
740 static int seccomp_do_user_notification(int this_syscall,
741 struct seccomp_filter *match,
742 const struct seccomp_data *sd)
747 struct seccomp_knotif n = {};
749 mutex_lock(&match->notify_lock);
755 n.state = SECCOMP_NOTIFY_INIT;
757 n.id = seccomp_next_notify_id(match);
758 init_completion(&n.ready);
759 list_add(&n.list, &match->notif->notifications);
761 up(&match->notif->request);
762 wake_up_poll(&match->notif->wqh, EPOLLIN | EPOLLRDNORM);
763 mutex_unlock(&match->notify_lock);
766 * This is where we wait for a reply from userspace.
768 err = wait_for_completion_interruptible(&n.ready);
769 mutex_lock(&match->notify_lock);
777 * Note that it's possible the listener died in between the time when
778 * we were notified of a respons (or a signal) and when we were able to
779 * re-acquire the lock, so only delete from the list if the
780 * notification actually exists.
782 * Also note that this test is only valid because there's no way to
783 * *reattach* to a notifier right now. If one is added, we'll need to
784 * keep track of the notif itself and make sure they match here.
789 mutex_unlock(&match->notify_lock);
791 /* Userspace requests to continue the syscall. */
792 if (flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE)
795 syscall_set_return_value(current, task_pt_regs(current),
800 static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
801 const bool recheck_after_trace)
803 u32 filter_ret, action;
804 struct seccomp_filter *match = NULL;
806 struct seccomp_data sd_local;
809 * Make sure that any changes to mode from another thread have
810 * been seen after TIF_SECCOMP was seen.
815 populate_seccomp_data(&sd_local);
819 filter_ret = seccomp_run_filters(sd, &match);
820 data = filter_ret & SECCOMP_RET_DATA;
821 action = filter_ret & SECCOMP_RET_ACTION_FULL;
824 case SECCOMP_RET_ERRNO:
825 /* Set low-order bits as an errno, capped at MAX_ERRNO. */
826 if (data > MAX_ERRNO)
828 syscall_set_return_value(current, task_pt_regs(current),
832 case SECCOMP_RET_TRAP:
833 /* Show the handler the original registers. */
834 syscall_rollback(current, task_pt_regs(current));
835 /* Let the filter pass back 16 bits of data. */
836 seccomp_send_sigsys(this_syscall, data);
839 case SECCOMP_RET_TRACE:
840 /* We've been put in this state by the ptracer already. */
841 if (recheck_after_trace)
844 /* ENOSYS these calls if there is no tracer attached. */
845 if (!ptrace_event_enabled(current, PTRACE_EVENT_SECCOMP)) {
846 syscall_set_return_value(current,
847 task_pt_regs(current),
852 /* Allow the BPF to provide the event message */
853 ptrace_event(PTRACE_EVENT_SECCOMP, data);
855 * The delivery of a fatal signal during event
856 * notification may silently skip tracer notification,
857 * which could leave us with a potentially unmodified
858 * syscall that the tracer would have liked to have
859 * changed. Since the process is about to die, we just
860 * force the syscall to be skipped and let the signal
861 * kill the process and correctly handle any tracer exit
864 if (fatal_signal_pending(current))
866 /* Check if the tracer forced the syscall to be skipped. */
867 this_syscall = syscall_get_nr(current, task_pt_regs(current));
868 if (this_syscall < 0)
872 * Recheck the syscall, since it may have changed. This
873 * intentionally uses a NULL struct seccomp_data to force
874 * a reload of all registers. This does not goto skip since
875 * a skip would have already been reported.
877 if (__seccomp_filter(this_syscall, NULL, true))
882 case SECCOMP_RET_USER_NOTIF:
883 if (seccomp_do_user_notification(this_syscall, match, sd))
888 case SECCOMP_RET_LOG:
889 seccomp_log(this_syscall, 0, action, true);
892 case SECCOMP_RET_ALLOW:
894 * Note that the "match" filter will always be NULL for
895 * this action since SECCOMP_RET_ALLOW is the starting
896 * state in seccomp_run_filters().
900 case SECCOMP_RET_KILL_THREAD:
901 case SECCOMP_RET_KILL_PROCESS:
903 seccomp_log(this_syscall, SIGSYS, action, true);
904 /* Dump core only if this is the last remaining thread. */
905 if (action == SECCOMP_RET_KILL_PROCESS ||
906 get_nr_threads(current) == 1) {
907 kernel_siginfo_t info;
909 /* Show the original registers in the dump. */
910 syscall_rollback(current, task_pt_regs(current));
911 /* Trigger a manual coredump since do_exit skips it. */
912 seccomp_init_siginfo(&info, this_syscall, data);
915 if (action == SECCOMP_RET_KILL_PROCESS)
916 do_group_exit(SIGSYS);
924 seccomp_log(this_syscall, 0, action, match ? match->log : false);
928 static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
929 const bool recheck_after_trace)
935 int __secure_computing(const struct seccomp_data *sd)
937 int mode = current->seccomp.mode;
940 if (IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) &&
941 unlikely(current->ptrace & PT_SUSPEND_SECCOMP))
944 this_syscall = sd ? sd->nr :
945 syscall_get_nr(current, task_pt_regs(current));
948 case SECCOMP_MODE_STRICT:
949 __secure_computing_strict(this_syscall); /* may call do_exit */
951 case SECCOMP_MODE_FILTER:
952 return __seccomp_filter(this_syscall, sd, false);
957 #endif /* CONFIG_HAVE_ARCH_SECCOMP_FILTER */
959 long prctl_get_seccomp(void)
961 return current->seccomp.mode;
965 * seccomp_set_mode_strict: internal function for setting strict seccomp
967 * Once current->seccomp.mode is non-zero, it may not be changed.
969 * Returns 0 on success or -EINVAL on failure.
971 static long seccomp_set_mode_strict(void)
973 const unsigned long seccomp_mode = SECCOMP_MODE_STRICT;
976 spin_lock_irq(¤t->sighand->siglock);
978 if (!seccomp_may_assign_mode(seccomp_mode))
984 seccomp_assign_mode(current, seccomp_mode, 0);
988 spin_unlock_irq(¤t->sighand->siglock);
993 #ifdef CONFIG_SECCOMP_FILTER
994 static int seccomp_notify_release(struct inode *inode, struct file *file)
996 struct seccomp_filter *filter = file->private_data;
997 struct seccomp_knotif *knotif;
1002 mutex_lock(&filter->notify_lock);
1005 * If this file is being closed because e.g. the task who owned it
1006 * died, let's wake everyone up who was waiting on us.
1008 list_for_each_entry(knotif, &filter->notif->notifications, list) {
1009 if (knotif->state == SECCOMP_NOTIFY_REPLIED)
1012 knotif->state = SECCOMP_NOTIFY_REPLIED;
1013 knotif->error = -ENOSYS;
1016 complete(&knotif->ready);
1019 kfree(filter->notif);
1020 filter->notif = NULL;
1021 mutex_unlock(&filter->notify_lock);
1022 __put_seccomp_filter(filter);
1026 static long seccomp_notify_recv(struct seccomp_filter *filter,
1029 struct seccomp_knotif *knotif = NULL, *cur;
1030 struct seccomp_notif unotif;
1033 /* Verify that we're not given garbage to keep struct extensible. */
1034 ret = check_zeroed_user(buf, sizeof(unotif));
1040 memset(&unotif, 0, sizeof(unotif));
1042 ret = down_interruptible(&filter->notif->request);
1046 mutex_lock(&filter->notify_lock);
1047 list_for_each_entry(cur, &filter->notif->notifications, list) {
1048 if (cur->state == SECCOMP_NOTIFY_INIT) {
1055 * If we didn't find a notification, it could be that the task was
1056 * interrupted by a fatal signal between the time we were woken and
1057 * when we were able to acquire the rw lock.
1064 unotif.id = knotif->id;
1065 unotif.pid = task_pid_vnr(knotif->task);
1066 unotif.data = *(knotif->data);
1068 knotif->state = SECCOMP_NOTIFY_SENT;
1069 wake_up_poll(&filter->notif->wqh, EPOLLOUT | EPOLLWRNORM);
1072 mutex_unlock(&filter->notify_lock);
1074 if (ret == 0 && copy_to_user(buf, &unotif, sizeof(unotif))) {
1078 * Userspace screwed up. To make sure that we keep this
1079 * notification alive, let's reset it back to INIT. It
1080 * may have died when we released the lock, so we need to make
1081 * sure it's still around.
1084 mutex_lock(&filter->notify_lock);
1085 list_for_each_entry(cur, &filter->notif->notifications, list) {
1086 if (cur->id == unotif.id) {
1093 knotif->state = SECCOMP_NOTIFY_INIT;
1094 up(&filter->notif->request);
1096 mutex_unlock(&filter->notify_lock);
1102 static long seccomp_notify_send(struct seccomp_filter *filter,
1105 struct seccomp_notif_resp resp = {};
1106 struct seccomp_knotif *knotif = NULL, *cur;
1109 if (copy_from_user(&resp, buf, sizeof(resp)))
1112 if (resp.flags & ~SECCOMP_USER_NOTIF_FLAG_CONTINUE)
1115 if ((resp.flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE) &&
1116 (resp.error || resp.val))
1119 ret = mutex_lock_interruptible(&filter->notify_lock);
1123 list_for_each_entry(cur, &filter->notif->notifications, list) {
1124 if (cur->id == resp.id) {
1135 /* Allow exactly one reply. */
1136 if (knotif->state != SECCOMP_NOTIFY_SENT) {
1142 knotif->state = SECCOMP_NOTIFY_REPLIED;
1143 knotif->error = resp.error;
1144 knotif->val = resp.val;
1145 knotif->flags = resp.flags;
1146 complete(&knotif->ready);
1148 mutex_unlock(&filter->notify_lock);
1152 static long seccomp_notify_id_valid(struct seccomp_filter *filter,
1155 struct seccomp_knotif *knotif = NULL;
1159 if (copy_from_user(&id, buf, sizeof(id)))
1162 ret = mutex_lock_interruptible(&filter->notify_lock);
1167 list_for_each_entry(knotif, &filter->notif->notifications, list) {
1168 if (knotif->id == id) {
1169 if (knotif->state == SECCOMP_NOTIFY_SENT)
1176 mutex_unlock(&filter->notify_lock);
1180 static long seccomp_notify_ioctl(struct file *file, unsigned int cmd,
1183 struct seccomp_filter *filter = file->private_data;
1184 void __user *buf = (void __user *)arg;
1187 case SECCOMP_IOCTL_NOTIF_RECV:
1188 return seccomp_notify_recv(filter, buf);
1189 case SECCOMP_IOCTL_NOTIF_SEND:
1190 return seccomp_notify_send(filter, buf);
1191 case SECCOMP_IOCTL_NOTIF_ID_VALID:
1192 return seccomp_notify_id_valid(filter, buf);
1198 static __poll_t seccomp_notify_poll(struct file *file,
1199 struct poll_table_struct *poll_tab)
1201 struct seccomp_filter *filter = file->private_data;
1203 struct seccomp_knotif *cur;
1205 poll_wait(file, &filter->notif->wqh, poll_tab);
1207 if (mutex_lock_interruptible(&filter->notify_lock) < 0)
1210 list_for_each_entry(cur, &filter->notif->notifications, list) {
1211 if (cur->state == SECCOMP_NOTIFY_INIT)
1212 ret |= EPOLLIN | EPOLLRDNORM;
1213 if (cur->state == SECCOMP_NOTIFY_SENT)
1214 ret |= EPOLLOUT | EPOLLWRNORM;
1215 if ((ret & EPOLLIN) && (ret & EPOLLOUT))
1219 mutex_unlock(&filter->notify_lock);
1224 static const struct file_operations seccomp_notify_ops = {
1225 .poll = seccomp_notify_poll,
1226 .release = seccomp_notify_release,
1227 .unlocked_ioctl = seccomp_notify_ioctl,
1228 .compat_ioctl = seccomp_notify_ioctl,
1231 static struct file *init_listener(struct seccomp_filter *filter)
1233 struct file *ret = ERR_PTR(-EBUSY);
1234 struct seccomp_filter *cur;
1236 for (cur = current->seccomp.filter; cur; cur = cur->prev) {
1241 ret = ERR_PTR(-ENOMEM);
1242 filter->notif = kzalloc(sizeof(*(filter->notif)), GFP_KERNEL);
1246 sema_init(&filter->notif->request, 0);
1247 filter->notif->next_id = get_random_u64();
1248 INIT_LIST_HEAD(&filter->notif->notifications);
1249 init_waitqueue_head(&filter->notif->wqh);
1251 ret = anon_inode_getfile("seccomp notify", &seccomp_notify_ops,
1256 /* The file has a reference to it now */
1257 __get_seccomp_filter(filter);
1261 kfree(filter->notif);
1267 * seccomp_set_mode_filter: internal function for setting seccomp filter
1268 * @flags: flags to change filter behavior
1269 * @filter: struct sock_fprog containing filter
1271 * This function may be called repeatedly to install additional filters.
1272 * Every filter successfully installed will be evaluated (in reverse order)
1273 * for each system call the task makes.
1275 * Once current->seccomp.mode is non-zero, it may not be changed.
1277 * Returns 0 on success or -EINVAL on failure.
1279 static long seccomp_set_mode_filter(unsigned int flags,
1280 const char __user *filter)
1282 const unsigned long seccomp_mode = SECCOMP_MODE_FILTER;
1283 struct seccomp_filter *prepared = NULL;
1286 struct file *listener_f = NULL;
1288 /* Validate flags. */
1289 if (flags & ~SECCOMP_FILTER_FLAG_MASK)
1293 * In the successful case, NEW_LISTENER returns the new listener fd.
1294 * But in the failure case, TSYNC returns the thread that died. If you
1295 * combine these two flags, there's no way to tell whether something
1296 * succeeded or failed. So, let's disallow this combination if the user
1297 * has not explicitly requested no errors from TSYNC.
1299 if ((flags & SECCOMP_FILTER_FLAG_TSYNC) &&
1300 (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) &&
1301 ((flags & SECCOMP_FILTER_FLAG_TSYNC_ESRCH) == 0))
1304 /* Prepare the new filter before holding any locks. */
1305 prepared = seccomp_prepare_user_filter(filter);
1306 if (IS_ERR(prepared))
1307 return PTR_ERR(prepared);
1309 if (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) {
1310 listener = get_unused_fd_flags(O_CLOEXEC);
1316 listener_f = init_listener(prepared);
1317 if (IS_ERR(listener_f)) {
1318 put_unused_fd(listener);
1319 ret = PTR_ERR(listener_f);
1325 * Make sure we cannot change seccomp or nnp state via TSYNC
1326 * while another thread is in the middle of calling exec.
1328 if (flags & SECCOMP_FILTER_FLAG_TSYNC &&
1329 mutex_lock_killable(¤t->signal->cred_guard_mutex))
1332 spin_lock_irq(¤t->sighand->siglock);
1334 if (!seccomp_may_assign_mode(seccomp_mode))
1337 ret = seccomp_attach_filter(flags, prepared);
1340 /* Do not free the successfully attached filter. */
1343 seccomp_assign_mode(current, seccomp_mode, flags);
1345 spin_unlock_irq(¤t->sighand->siglock);
1346 if (flags & SECCOMP_FILTER_FLAG_TSYNC)
1347 mutex_unlock(¤t->signal->cred_guard_mutex);
1349 if (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) {
1351 listener_f->private_data = NULL;
1353 put_unused_fd(listener);
1355 fd_install(listener, listener_f);
1360 seccomp_filter_free(prepared);
1364 static inline long seccomp_set_mode_filter(unsigned int flags,
1365 const char __user *filter)
1371 static long seccomp_get_action_avail(const char __user *uaction)
1375 if (copy_from_user(&action, uaction, sizeof(action)))
1379 case SECCOMP_RET_KILL_PROCESS:
1380 case SECCOMP_RET_KILL_THREAD:
1381 case SECCOMP_RET_TRAP:
1382 case SECCOMP_RET_ERRNO:
1383 case SECCOMP_RET_USER_NOTIF:
1384 case SECCOMP_RET_TRACE:
1385 case SECCOMP_RET_LOG:
1386 case SECCOMP_RET_ALLOW:
1395 static long seccomp_get_notif_sizes(void __user *usizes)
1397 struct seccomp_notif_sizes sizes = {
1398 .seccomp_notif = sizeof(struct seccomp_notif),
1399 .seccomp_notif_resp = sizeof(struct seccomp_notif_resp),
1400 .seccomp_data = sizeof(struct seccomp_data),
1403 if (copy_to_user(usizes, &sizes, sizeof(sizes)))
1409 /* Common entry point for both prctl and syscall. */
1410 static long do_seccomp(unsigned int op, unsigned int flags,
1414 case SECCOMP_SET_MODE_STRICT:
1415 if (flags != 0 || uargs != NULL)
1417 return seccomp_set_mode_strict();
1418 case SECCOMP_SET_MODE_FILTER:
1419 return seccomp_set_mode_filter(flags, uargs);
1420 case SECCOMP_GET_ACTION_AVAIL:
1424 return seccomp_get_action_avail(uargs);
1425 case SECCOMP_GET_NOTIF_SIZES:
1429 return seccomp_get_notif_sizes(uargs);
1435 SYSCALL_DEFINE3(seccomp, unsigned int, op, unsigned int, flags,
1436 void __user *, uargs)
1438 return do_seccomp(op, flags, uargs);
1442 * prctl_set_seccomp: configures current->seccomp.mode
1443 * @seccomp_mode: requested mode to use
1444 * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER
1446 * Returns 0 on success or -EINVAL on failure.
1448 long prctl_set_seccomp(unsigned long seccomp_mode, void __user *filter)
1453 switch (seccomp_mode) {
1454 case SECCOMP_MODE_STRICT:
1455 op = SECCOMP_SET_MODE_STRICT;
1457 * Setting strict mode through prctl always ignored filter,
1458 * so make sure it is always NULL here to pass the internal
1459 * check in do_seccomp().
1463 case SECCOMP_MODE_FILTER:
1464 op = SECCOMP_SET_MODE_FILTER;
1471 /* prctl interface doesn't have flags, so they are always zero. */
1472 return do_seccomp(op, 0, uargs);
1475 #if defined(CONFIG_SECCOMP_FILTER) && defined(CONFIG_CHECKPOINT_RESTORE)
1476 static struct seccomp_filter *get_nth_filter(struct task_struct *task,
1477 unsigned long filter_off)
1479 struct seccomp_filter *orig, *filter;
1480 unsigned long count;
1483 * Note: this is only correct because the caller should be the (ptrace)
1484 * tracer of the task, otherwise lock_task_sighand is needed.
1486 spin_lock_irq(&task->sighand->siglock);
1488 if (task->seccomp.mode != SECCOMP_MODE_FILTER) {
1489 spin_unlock_irq(&task->sighand->siglock);
1490 return ERR_PTR(-EINVAL);
1493 orig = task->seccomp.filter;
1494 __get_seccomp_filter(orig);
1495 spin_unlock_irq(&task->sighand->siglock);
1498 for (filter = orig; filter; filter = filter->prev)
1501 if (filter_off >= count) {
1502 filter = ERR_PTR(-ENOENT);
1506 count -= filter_off;
1507 for (filter = orig; filter && count > 1; filter = filter->prev)
1510 if (WARN_ON(count != 1 || !filter)) {
1511 filter = ERR_PTR(-ENOENT);
1515 __get_seccomp_filter(filter);
1518 __put_seccomp_filter(orig);
1522 long seccomp_get_filter(struct task_struct *task, unsigned long filter_off,
1525 struct seccomp_filter *filter;
1526 struct sock_fprog_kern *fprog;
1529 if (!capable(CAP_SYS_ADMIN) ||
1530 current->seccomp.mode != SECCOMP_MODE_DISABLED) {
1534 filter = get_nth_filter(task, filter_off);
1536 return PTR_ERR(filter);
1538 fprog = filter->prog->orig_prog;
1540 /* This must be a new non-cBPF filter, since we save
1541 * every cBPF filter's orig_prog above when
1542 * CONFIG_CHECKPOINT_RESTORE is enabled.
1552 if (copy_to_user(data, fprog->filter, bpf_classic_proglen(fprog)))
1556 __put_seccomp_filter(filter);
1560 long seccomp_get_metadata(struct task_struct *task,
1561 unsigned long size, void __user *data)
1564 struct seccomp_filter *filter;
1565 struct seccomp_metadata kmd = {};
1567 if (!capable(CAP_SYS_ADMIN) ||
1568 current->seccomp.mode != SECCOMP_MODE_DISABLED) {
1572 size = min_t(unsigned long, size, sizeof(kmd));
1574 if (size < sizeof(kmd.filter_off))
1577 if (copy_from_user(&kmd.filter_off, data, sizeof(kmd.filter_off)))
1580 filter = get_nth_filter(task, kmd.filter_off);
1582 return PTR_ERR(filter);
1585 kmd.flags |= SECCOMP_FILTER_FLAG_LOG;
1588 if (copy_to_user(data, &kmd, size))
1591 __put_seccomp_filter(filter);
1596 #ifdef CONFIG_SYSCTL
1598 /* Human readable action names for friendly sysctl interaction */
1599 #define SECCOMP_RET_KILL_PROCESS_NAME "kill_process"
1600 #define SECCOMP_RET_KILL_THREAD_NAME "kill_thread"
1601 #define SECCOMP_RET_TRAP_NAME "trap"
1602 #define SECCOMP_RET_ERRNO_NAME "errno"
1603 #define SECCOMP_RET_USER_NOTIF_NAME "user_notif"
1604 #define SECCOMP_RET_TRACE_NAME "trace"
1605 #define SECCOMP_RET_LOG_NAME "log"
1606 #define SECCOMP_RET_ALLOW_NAME "allow"
1608 static const char seccomp_actions_avail[] =
1609 SECCOMP_RET_KILL_PROCESS_NAME " "
1610 SECCOMP_RET_KILL_THREAD_NAME " "
1611 SECCOMP_RET_TRAP_NAME " "
1612 SECCOMP_RET_ERRNO_NAME " "
1613 SECCOMP_RET_USER_NOTIF_NAME " "
1614 SECCOMP_RET_TRACE_NAME " "
1615 SECCOMP_RET_LOG_NAME " "
1616 SECCOMP_RET_ALLOW_NAME;
1618 struct seccomp_log_name {
1623 static const struct seccomp_log_name seccomp_log_names[] = {
1624 { SECCOMP_LOG_KILL_PROCESS, SECCOMP_RET_KILL_PROCESS_NAME },
1625 { SECCOMP_LOG_KILL_THREAD, SECCOMP_RET_KILL_THREAD_NAME },
1626 { SECCOMP_LOG_TRAP, SECCOMP_RET_TRAP_NAME },
1627 { SECCOMP_LOG_ERRNO, SECCOMP_RET_ERRNO_NAME },
1628 { SECCOMP_LOG_USER_NOTIF, SECCOMP_RET_USER_NOTIF_NAME },
1629 { SECCOMP_LOG_TRACE, SECCOMP_RET_TRACE_NAME },
1630 { SECCOMP_LOG_LOG, SECCOMP_RET_LOG_NAME },
1631 { SECCOMP_LOG_ALLOW, SECCOMP_RET_ALLOW_NAME },
1635 static bool seccomp_names_from_actions_logged(char *names, size_t size,
1639 const struct seccomp_log_name *cur;
1640 bool append_sep = false;
1642 for (cur = seccomp_log_names; cur->name && size; cur++) {
1645 if (!(actions_logged & cur->log))
1649 ret = strscpy(names, sep, size);
1658 ret = strscpy(names, cur->name, size);
1669 static bool seccomp_action_logged_from_name(u32 *action_logged,
1672 const struct seccomp_log_name *cur;
1674 for (cur = seccomp_log_names; cur->name; cur++) {
1675 if (!strcmp(cur->name, name)) {
1676 *action_logged = cur->log;
1684 static bool seccomp_actions_logged_from_names(u32 *actions_logged, char *names)
1688 *actions_logged = 0;
1689 while ((name = strsep(&names, " ")) && *name) {
1690 u32 action_logged = 0;
1692 if (!seccomp_action_logged_from_name(&action_logged, name))
1695 *actions_logged |= action_logged;
1701 static int read_actions_logged(struct ctl_table *ro_table, void __user *buffer,
1702 size_t *lenp, loff_t *ppos)
1704 char names[sizeof(seccomp_actions_avail)];
1705 struct ctl_table table;
1707 memset(names, 0, sizeof(names));
1709 if (!seccomp_names_from_actions_logged(names, sizeof(names),
1710 seccomp_actions_logged, " "))
1715 table.maxlen = sizeof(names);
1716 return proc_dostring(&table, 0, buffer, lenp, ppos);
1719 static int write_actions_logged(struct ctl_table *ro_table, void __user *buffer,
1720 size_t *lenp, loff_t *ppos, u32 *actions_logged)
1722 char names[sizeof(seccomp_actions_avail)];
1723 struct ctl_table table;
1726 if (!capable(CAP_SYS_ADMIN))
1729 memset(names, 0, sizeof(names));
1733 table.maxlen = sizeof(names);
1734 ret = proc_dostring(&table, 1, buffer, lenp, ppos);
1738 if (!seccomp_actions_logged_from_names(actions_logged, table.data))
1741 if (*actions_logged & SECCOMP_LOG_ALLOW)
1744 seccomp_actions_logged = *actions_logged;
1748 static void audit_actions_logged(u32 actions_logged, u32 old_actions_logged,
1751 char names[sizeof(seccomp_actions_avail)];
1752 char old_names[sizeof(seccomp_actions_avail)];
1753 const char *new = names;
1754 const char *old = old_names;
1759 memset(names, 0, sizeof(names));
1760 memset(old_names, 0, sizeof(old_names));
1764 else if (!actions_logged)
1766 else if (!seccomp_names_from_actions_logged(names, sizeof(names),
1767 actions_logged, ","))
1770 if (!old_actions_logged)
1772 else if (!seccomp_names_from_actions_logged(old_names,
1774 old_actions_logged, ","))
1777 return audit_seccomp_actions_logged(new, old, !ret);
1780 static int seccomp_actions_logged_handler(struct ctl_table *ro_table, int write,
1781 void __user *buffer, size_t *lenp,
1787 u32 actions_logged = 0;
1788 u32 old_actions_logged = seccomp_actions_logged;
1790 ret = write_actions_logged(ro_table, buffer, lenp, ppos,
1792 audit_actions_logged(actions_logged, old_actions_logged, ret);
1794 ret = read_actions_logged(ro_table, buffer, lenp, ppos);
1799 static struct ctl_path seccomp_sysctl_path[] = {
1800 { .procname = "kernel", },
1801 { .procname = "seccomp", },
1805 static struct ctl_table seccomp_sysctl_table[] = {
1807 .procname = "actions_avail",
1808 .data = (void *) &seccomp_actions_avail,
1809 .maxlen = sizeof(seccomp_actions_avail),
1811 .proc_handler = proc_dostring,
1814 .procname = "actions_logged",
1816 .proc_handler = seccomp_actions_logged_handler,
1821 static int __init seccomp_sysctl_init(void)
1823 struct ctl_table_header *hdr;
1825 hdr = register_sysctl_paths(seccomp_sysctl_path, seccomp_sysctl_table);
1827 pr_warn("seccomp: sysctl registration failed\n");
1829 kmemleak_not_leak(hdr);
1834 device_initcall(seccomp_sysctl_init)
1836 #endif /* CONFIG_SYSCTL */