1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Task credentials management - see Documentation/security/credentials.rst
4 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) "CRED: " fmt
10 #include <linux/export.h>
11 #include <linux/cred.h>
12 #include <linux/slab.h>
13 #include <linux/sched.h>
14 #include <linux/sched/coredump.h>
15 #include <linux/key.h>
16 #include <linux/keyctl.h>
17 #include <linux/init_task.h>
18 #include <linux/security.h>
19 #include <linux/binfmts.h>
20 #include <linux/cn_proc.h>
21 #include <linux/uidgid.h>
24 #define kdebug(FMT, ...) \
25 printk("[%-5.5s%5u] " FMT "\n", \
26 current->comm, current->pid, ##__VA_ARGS__)
28 #define kdebug(FMT, ...) \
31 no_printk("[%-5.5s%5u] " FMT "\n", \
32 current->comm, current->pid, ##__VA_ARGS__); \
36 static struct kmem_cache *cred_jar;
38 /* init to 2 - one for init_task, one to ensure it is never freed */
39 static struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
42 * The initial credentials for the initial task
44 struct cred init_cred = {
45 .usage = ATOMIC_INIT(4),
46 #ifdef CONFIG_DEBUG_CREDENTIALS
47 .subscribers = ATOMIC_INIT(2),
50 .uid = GLOBAL_ROOT_UID,
51 .gid = GLOBAL_ROOT_GID,
52 .suid = GLOBAL_ROOT_UID,
53 .sgid = GLOBAL_ROOT_GID,
54 .euid = GLOBAL_ROOT_UID,
55 .egid = GLOBAL_ROOT_GID,
56 .fsuid = GLOBAL_ROOT_UID,
57 .fsgid = GLOBAL_ROOT_GID,
58 .securebits = SECUREBITS_DEFAULT,
59 .cap_inheritable = CAP_EMPTY_SET,
60 .cap_permitted = CAP_FULL_SET,
61 .cap_effective = CAP_FULL_SET,
62 .cap_bset = CAP_FULL_SET,
64 .user_ns = &init_user_ns,
65 .group_info = &init_groups,
66 .ucounts = &init_ucounts,
69 static inline void set_cred_subscribers(struct cred *cred, int n)
71 #ifdef CONFIG_DEBUG_CREDENTIALS
72 atomic_set(&cred->subscribers, n);
76 static inline int read_cred_subscribers(const struct cred *cred)
78 #ifdef CONFIG_DEBUG_CREDENTIALS
79 return atomic_read(&cred->subscribers);
85 static inline void alter_cred_subscribers(const struct cred *_cred, int n)
87 #ifdef CONFIG_DEBUG_CREDENTIALS
88 struct cred *cred = (struct cred *) _cred;
90 atomic_add(n, &cred->subscribers);
95 * The RCU callback to actually dispose of a set of credentials
97 static void put_cred_rcu(struct rcu_head *rcu)
99 struct cred *cred = container_of(rcu, struct cred, rcu);
101 kdebug("put_cred_rcu(%p)", cred);
103 #ifdef CONFIG_DEBUG_CREDENTIALS
104 if (cred->magic != CRED_MAGIC_DEAD ||
105 atomic_read(&cred->usage) != 0 ||
106 read_cred_subscribers(cred) != 0)
107 panic("CRED: put_cred_rcu() sees %p with"
108 " mag %x, put %p, usage %d, subscr %d\n",
109 cred, cred->magic, cred->put_addr,
110 atomic_read(&cred->usage),
111 read_cred_subscribers(cred));
113 if (atomic_read(&cred->usage) != 0)
114 panic("CRED: put_cred_rcu() sees %p with usage %d\n",
115 cred, atomic_read(&cred->usage));
118 security_cred_free(cred);
119 key_put(cred->session_keyring);
120 key_put(cred->process_keyring);
121 key_put(cred->thread_keyring);
122 key_put(cred->request_key_auth);
123 if (cred->group_info)
124 put_group_info(cred->group_info);
125 free_uid(cred->user);
127 put_ucounts(cred->ucounts);
128 put_user_ns(cred->user_ns);
129 kmem_cache_free(cred_jar, cred);
133 * __put_cred - Destroy a set of credentials
134 * @cred: The record to release
136 * Destroy a set of credentials on which no references remain.
138 void __put_cred(struct cred *cred)
140 kdebug("__put_cred(%p{%d,%d})", cred,
141 atomic_read(&cred->usage),
142 read_cred_subscribers(cred));
144 BUG_ON(atomic_read(&cred->usage) != 0);
145 #ifdef CONFIG_DEBUG_CREDENTIALS
146 BUG_ON(read_cred_subscribers(cred) != 0);
147 cred->magic = CRED_MAGIC_DEAD;
148 cred->put_addr = __builtin_return_address(0);
150 BUG_ON(cred == current->cred);
151 BUG_ON(cred == current->real_cred);
154 put_cred_rcu(&cred->rcu);
156 call_rcu(&cred->rcu, put_cred_rcu);
158 EXPORT_SYMBOL(__put_cred);
161 * Clean up a task's credentials when it exits
163 void exit_creds(struct task_struct *tsk)
167 kdebug("exit_creds(%u,%p,%p,{%d,%d})", tsk->pid, tsk->real_cred, tsk->cred,
168 atomic_read(&tsk->cred->usage),
169 read_cred_subscribers(tsk->cred));
171 cred = (struct cred *) tsk->real_cred;
172 tsk->real_cred = NULL;
173 validate_creds(cred);
174 alter_cred_subscribers(cred, -1);
177 cred = (struct cred *) tsk->cred;
179 validate_creds(cred);
180 alter_cred_subscribers(cred, -1);
183 #ifdef CONFIG_KEYS_REQUEST_CACHE
184 key_put(tsk->cached_requested_key);
185 tsk->cached_requested_key = NULL;
190 * get_task_cred - Get another task's objective credentials
191 * @task: The task to query
193 * Get the objective credentials of a task, pinning them so that they can't go
194 * away. Accessing a task's credentials directly is not permitted.
196 * The caller must also make sure task doesn't get deleted, either by holding a
197 * ref on task or by holding tasklist_lock to prevent it from being unlinked.
199 const struct cred *get_task_cred(struct task_struct *task)
201 const struct cred *cred;
206 cred = __task_cred((task));
208 } while (!get_cred_rcu(cred));
213 EXPORT_SYMBOL(get_task_cred);
216 * Allocate blank credentials, such that the credentials can be filled in at a
217 * later date without risk of ENOMEM.
219 struct cred *cred_alloc_blank(void)
223 new = kmem_cache_zalloc(cred_jar, GFP_KERNEL);
227 atomic_set(&new->usage, 1);
228 #ifdef CONFIG_DEBUG_CREDENTIALS
229 new->magic = CRED_MAGIC;
231 if (security_cred_alloc_blank(new, GFP_KERNEL_ACCOUNT) < 0)
242 * prepare_creds - Prepare a new set of credentials for modification
244 * Prepare a new set of task credentials for modification. A task's creds
245 * shouldn't generally be modified directly, therefore this function is used to
246 * prepare a new copy, which the caller then modifies and then commits by
247 * calling commit_creds().
249 * Preparation involves making a copy of the objective creds for modification.
251 * Returns a pointer to the new creds-to-be if successful, NULL otherwise.
253 * Call commit_creds() or abort_creds() to clean up.
255 struct cred *prepare_creds(void)
257 struct task_struct *task = current;
258 const struct cred *old;
261 validate_process_creds();
263 new = kmem_cache_alloc(cred_jar, GFP_KERNEL);
267 kdebug("prepare_creds() alloc %p", new);
270 memcpy(new, old, sizeof(struct cred));
273 atomic_set(&new->usage, 1);
274 set_cred_subscribers(new, 0);
275 get_group_info(new->group_info);
277 get_user_ns(new->user_ns);
280 key_get(new->session_keyring);
281 key_get(new->process_keyring);
282 key_get(new->thread_keyring);
283 key_get(new->request_key_auth);
286 #ifdef CONFIG_SECURITY
287 new->security = NULL;
290 new->ucounts = get_ucounts(new->ucounts);
294 if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
304 EXPORT_SYMBOL(prepare_creds);
307 * Prepare credentials for current to perform an execve()
308 * - The caller must hold ->cred_guard_mutex
310 struct cred *prepare_exec_creds(void)
314 new = prepare_creds();
319 /* newly exec'd tasks don't get a thread keyring */
320 key_put(new->thread_keyring);
321 new->thread_keyring = NULL;
323 /* inherit the session keyring; new process keyring */
324 key_put(new->process_keyring);
325 new->process_keyring = NULL;
328 new->suid = new->fsuid = new->euid;
329 new->sgid = new->fsgid = new->egid;
335 * Copy credentials for the new process created by fork()
337 * We share if we can, but under some circumstances we have to generate a new
340 * The new process gets the current process's subjective credentials as its
341 * objective and subjective credentials
343 int copy_creds(struct task_struct *p, unsigned long clone_flags)
348 #ifdef CONFIG_KEYS_REQUEST_CACHE
349 p->cached_requested_key = NULL;
354 !p->cred->thread_keyring &&
356 clone_flags & CLONE_THREAD
358 p->real_cred = get_cred(p->cred);
360 alter_cred_subscribers(p->cred, 2);
361 kdebug("share_creds(%p{%d,%d})",
362 p->cred, atomic_read(&p->cred->usage),
363 read_cred_subscribers(p->cred));
364 inc_rlimit_ucounts(task_ucounts(p), UCOUNT_RLIMIT_NPROC, 1);
368 new = prepare_creds();
372 if (clone_flags & CLONE_NEWUSER) {
373 ret = create_user_ns(new);
376 ret = set_cred_ucounts(new);
382 /* new threads get their own thread keyrings if their parent already
384 if (new->thread_keyring) {
385 key_put(new->thread_keyring);
386 new->thread_keyring = NULL;
387 if (clone_flags & CLONE_THREAD)
388 install_thread_keyring_to_cred(new);
391 /* The process keyring is only shared between the threads in a process;
392 * anything outside of those threads doesn't inherit.
394 if (!(clone_flags & CLONE_THREAD)) {
395 key_put(new->process_keyring);
396 new->process_keyring = NULL;
400 p->cred = p->real_cred = get_cred(new);
401 inc_rlimit_ucounts(task_ucounts(p), UCOUNT_RLIMIT_NPROC, 1);
402 alter_cred_subscribers(new, 2);
411 static bool cred_cap_issubset(const struct cred *set, const struct cred *subset)
413 const struct user_namespace *set_ns = set->user_ns;
414 const struct user_namespace *subset_ns = subset->user_ns;
416 /* If the two credentials are in the same user namespace see if
417 * the capabilities of subset are a subset of set.
419 if (set_ns == subset_ns)
420 return cap_issubset(subset->cap_permitted, set->cap_permitted);
422 /* The credentials are in a different user namespaces
423 * therefore one is a subset of the other only if a set is an
424 * ancestor of subset and set->euid is owner of subset or one
425 * of subsets ancestors.
427 for (;subset_ns != &init_user_ns; subset_ns = subset_ns->parent) {
428 if ((set_ns == subset_ns->parent) &&
429 uid_eq(subset_ns->owner, set->euid))
437 * commit_creds - Install new credentials upon the current task
438 * @new: The credentials to be assigned
440 * Install a new set of credentials to the current task, using RCU to replace
441 * the old set. Both the objective and the subjective credentials pointers are
442 * updated. This function may not be called if the subjective credentials are
443 * in an overridden state.
445 * This function eats the caller's reference to the new credentials.
447 * Always returns 0 thus allowing this function to be tail-called at the end
448 * of, say, sys_setgid().
450 int commit_creds(struct cred *new)
452 struct task_struct *task = current;
453 const struct cred *old = task->real_cred;
455 kdebug("commit_creds(%p{%d,%d})", new,
456 atomic_read(&new->usage),
457 read_cred_subscribers(new));
459 BUG_ON(task->cred != old);
460 #ifdef CONFIG_DEBUG_CREDENTIALS
461 BUG_ON(read_cred_subscribers(old) < 2);
465 BUG_ON(atomic_read(&new->usage) < 1);
467 get_cred(new); /* we will require a ref for the subj creds too */
469 /* dumpability changes */
470 if (!uid_eq(old->euid, new->euid) ||
471 !gid_eq(old->egid, new->egid) ||
472 !uid_eq(old->fsuid, new->fsuid) ||
473 !gid_eq(old->fsgid, new->fsgid) ||
474 !cred_cap_issubset(old, new)) {
476 set_dumpable(task->mm, suid_dumpable);
477 task->pdeath_signal = 0;
479 * If a task drops privileges and becomes nondumpable,
480 * the dumpability change must become visible before
481 * the credential change; otherwise, a __ptrace_may_access()
482 * racing with this change may be able to attach to a task it
483 * shouldn't be able to attach to (as if the task had dropped
484 * privileges without becoming nondumpable).
485 * Pairs with a read barrier in __ptrace_may_access().
490 /* alter the thread keyring */
491 if (!uid_eq(new->fsuid, old->fsuid))
492 key_fsuid_changed(new);
493 if (!gid_eq(new->fsgid, old->fsgid))
494 key_fsgid_changed(new);
497 * RLIMIT_NPROC limits on user->processes have already been checked
500 alter_cred_subscribers(new, 2);
501 if (new->user != old->user || new->user_ns != old->user_ns)
502 inc_rlimit_ucounts(new->ucounts, UCOUNT_RLIMIT_NPROC, 1);
503 rcu_assign_pointer(task->real_cred, new);
504 rcu_assign_pointer(task->cred, new);
505 if (new->user != old->user || new->user_ns != old->user_ns)
506 dec_rlimit_ucounts(old->ucounts, UCOUNT_RLIMIT_NPROC, 1);
507 alter_cred_subscribers(old, -2);
509 /* send notifications */
510 if (!uid_eq(new->uid, old->uid) ||
511 !uid_eq(new->euid, old->euid) ||
512 !uid_eq(new->suid, old->suid) ||
513 !uid_eq(new->fsuid, old->fsuid))
514 proc_id_connector(task, PROC_EVENT_UID);
516 if (!gid_eq(new->gid, old->gid) ||
517 !gid_eq(new->egid, old->egid) ||
518 !gid_eq(new->sgid, old->sgid) ||
519 !gid_eq(new->fsgid, old->fsgid))
520 proc_id_connector(task, PROC_EVENT_GID);
522 /* release the old obj and subj refs both */
527 EXPORT_SYMBOL(commit_creds);
530 * abort_creds - Discard a set of credentials and unlock the current task
531 * @new: The credentials that were going to be applied
533 * Discard a set of credentials that were under construction and unlock the
536 void abort_creds(struct cred *new)
538 kdebug("abort_creds(%p{%d,%d})", new,
539 atomic_read(&new->usage),
540 read_cred_subscribers(new));
542 #ifdef CONFIG_DEBUG_CREDENTIALS
543 BUG_ON(read_cred_subscribers(new) != 0);
545 BUG_ON(atomic_read(&new->usage) < 1);
548 EXPORT_SYMBOL(abort_creds);
551 * override_creds - Override the current process's subjective credentials
552 * @new: The credentials to be assigned
554 * Install a set of temporary override subjective credentials on the current
555 * process, returning the old set for later reversion.
557 const struct cred *override_creds(const struct cred *new)
559 const struct cred *old = current->cred;
561 kdebug("override_creds(%p{%d,%d})", new,
562 atomic_read(&new->usage),
563 read_cred_subscribers(new));
569 * NOTE! This uses 'get_new_cred()' rather than 'get_cred()'.
571 * That means that we do not clear the 'non_rcu' flag, since
572 * we are only installing the cred into the thread-synchronous
573 * '->cred' pointer, not the '->real_cred' pointer that is
574 * visible to other threads under RCU.
576 * Also note that we did validate_creds() manually, not depending
577 * on the validation in 'get_cred()'.
579 get_new_cred((struct cred *)new);
580 alter_cred_subscribers(new, 1);
581 rcu_assign_pointer(current->cred, new);
582 alter_cred_subscribers(old, -1);
584 kdebug("override_creds() = %p{%d,%d}", old,
585 atomic_read(&old->usage),
586 read_cred_subscribers(old));
589 EXPORT_SYMBOL(override_creds);
592 * revert_creds - Revert a temporary subjective credentials override
593 * @old: The credentials to be restored
595 * Revert a temporary set of override subjective credentials to an old set,
596 * discarding the override set.
598 void revert_creds(const struct cred *old)
600 const struct cred *override = current->cred;
602 kdebug("revert_creds(%p{%d,%d})", old,
603 atomic_read(&old->usage),
604 read_cred_subscribers(old));
607 validate_creds(override);
608 alter_cred_subscribers(old, 1);
609 rcu_assign_pointer(current->cred, old);
610 alter_cred_subscribers(override, -1);
613 EXPORT_SYMBOL(revert_creds);
616 * cred_fscmp - Compare two credentials with respect to filesystem access.
617 * @a: The first credential
618 * @b: The second credential
620 * cred_cmp() will return zero if both credentials have the same
621 * fsuid, fsgid, and supplementary groups. That is, if they will both
622 * provide the same access to files based on mode/uid/gid.
623 * If the credentials are different, then either -1 or 1 will
624 * be returned depending on whether @a comes before or after @b
625 * respectively in an arbitrary, but stable, ordering of credentials.
627 * Return: -1, 0, or 1 depending on comparison
629 int cred_fscmp(const struct cred *a, const struct cred *b)
631 struct group_info *ga, *gb;
636 if (uid_lt(a->fsuid, b->fsuid))
638 if (uid_gt(a->fsuid, b->fsuid))
641 if (gid_lt(a->fsgid, b->fsgid))
643 if (gid_gt(a->fsgid, b->fsgid))
654 if (ga->ngroups < gb->ngroups)
656 if (ga->ngroups > gb->ngroups)
659 for (g = 0; g < ga->ngroups; g++) {
660 if (gid_lt(ga->gid[g], gb->gid[g]))
662 if (gid_gt(ga->gid[g], gb->gid[g]))
667 EXPORT_SYMBOL(cred_fscmp);
669 int set_cred_ucounts(struct cred *new)
671 struct ucounts *new_ucounts, *old_ucounts = new->ucounts;
674 * This optimization is needed because alloc_ucounts() uses locks
677 if (old_ucounts->ns == new->user_ns && uid_eq(old_ucounts->uid, new->uid))
680 if (!(new_ucounts = alloc_ucounts(new->user_ns, new->uid)))
683 new->ucounts = new_ucounts;
684 put_ucounts(old_ucounts);
690 * initialise the credentials stuff
692 void __init cred_init(void)
694 /* allocate a slab in which we can store credentials */
695 cred_jar = kmem_cache_create("cred_jar", sizeof(struct cred), 0,
696 SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, NULL);
700 * prepare_kernel_cred - Prepare a set of credentials for a kernel service
701 * @daemon: A userspace daemon to be used as a reference
703 * Prepare a set of credentials for a kernel service. This can then be used to
704 * override a task's own credentials so that work can be done on behalf of that
705 * task that requires a different subjective context.
707 * @daemon is used to provide a base cred, with the security data derived from
708 * that; if this is "&init_task", they'll be set to 0, no groups, full
709 * capabilities, and no keys.
711 * The caller may change these controls afterwards if desired.
713 * Returns the new credentials or NULL if out of memory.
715 struct cred *prepare_kernel_cred(struct task_struct *daemon)
717 const struct cred *old;
720 if (WARN_ON_ONCE(!daemon))
723 new = kmem_cache_alloc(cred_jar, GFP_KERNEL);
727 kdebug("prepare_kernel_cred() alloc %p", new);
729 old = get_task_cred(daemon);
734 atomic_set(&new->usage, 1);
735 set_cred_subscribers(new, 0);
737 get_user_ns(new->user_ns);
738 get_group_info(new->group_info);
741 new->session_keyring = NULL;
742 new->process_keyring = NULL;
743 new->thread_keyring = NULL;
744 new->request_key_auth = NULL;
745 new->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
748 #ifdef CONFIG_SECURITY
749 new->security = NULL;
751 new->ucounts = get_ucounts(new->ucounts);
755 if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
767 EXPORT_SYMBOL(prepare_kernel_cred);
770 * set_security_override - Set the security ID in a set of credentials
771 * @new: The credentials to alter
772 * @secid: The LSM security ID to set
774 * Set the LSM security ID in a set of credentials so that the subjective
775 * security is overridden when an alternative set of credentials is used.
777 int set_security_override(struct cred *new, u32 secid)
779 return security_kernel_act_as(new, secid);
781 EXPORT_SYMBOL(set_security_override);
784 * set_security_override_from_ctx - Set the security ID in a set of credentials
785 * @new: The credentials to alter
786 * @secctx: The LSM security context to generate the security ID from.
788 * Set the LSM security ID in a set of credentials so that the subjective
789 * security is overridden when an alternative set of credentials is used. The
790 * security ID is specified in string form as a security context to be
791 * interpreted by the LSM.
793 int set_security_override_from_ctx(struct cred *new, const char *secctx)
798 ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
802 return set_security_override(new, secid);
804 EXPORT_SYMBOL(set_security_override_from_ctx);
807 * set_create_files_as - Set the LSM file create context in a set of credentials
808 * @new: The credentials to alter
809 * @inode: The inode to take the context from
811 * Change the LSM file creation context in a set of credentials to be the same
812 * as the object context of the specified inode, so that the new inodes have
813 * the same MAC context as that inode.
815 int set_create_files_as(struct cred *new, struct inode *inode)
817 if (!uid_valid(inode->i_uid) || !gid_valid(inode->i_gid))
819 new->fsuid = inode->i_uid;
820 new->fsgid = inode->i_gid;
821 return security_kernel_create_files_as(new, inode);
823 EXPORT_SYMBOL(set_create_files_as);
825 #ifdef CONFIG_DEBUG_CREDENTIALS
827 bool creds_are_invalid(const struct cred *cred)
829 if (cred->magic != CRED_MAGIC)
833 EXPORT_SYMBOL(creds_are_invalid);
836 * dump invalid credentials
838 static void dump_invalid_creds(const struct cred *cred, const char *label,
839 const struct task_struct *tsk)
841 pr_err("%s credentials: %p %s%s%s\n",
843 cred == &init_cred ? "[init]" : "",
844 cred == tsk->real_cred ? "[real]" : "",
845 cred == tsk->cred ? "[eff]" : "");
846 pr_err("->magic=%x, put_addr=%p\n",
847 cred->magic, cred->put_addr);
848 pr_err("->usage=%d, subscr=%d\n",
849 atomic_read(&cred->usage),
850 read_cred_subscribers(cred));
851 pr_err("->*uid = { %d,%d,%d,%d }\n",
852 from_kuid_munged(&init_user_ns, cred->uid),
853 from_kuid_munged(&init_user_ns, cred->euid),
854 from_kuid_munged(&init_user_ns, cred->suid),
855 from_kuid_munged(&init_user_ns, cred->fsuid));
856 pr_err("->*gid = { %d,%d,%d,%d }\n",
857 from_kgid_munged(&init_user_ns, cred->gid),
858 from_kgid_munged(&init_user_ns, cred->egid),
859 from_kgid_munged(&init_user_ns, cred->sgid),
860 from_kgid_munged(&init_user_ns, cred->fsgid));
861 #ifdef CONFIG_SECURITY
862 pr_err("->security is %p\n", cred->security);
863 if ((unsigned long) cred->security >= PAGE_SIZE &&
864 (((unsigned long) cred->security & 0xffffff00) !=
865 (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8)))
866 pr_err("->security {%x, %x}\n",
867 ((u32*)cred->security)[0],
868 ((u32*)cred->security)[1]);
873 * report use of invalid credentials
875 void __noreturn __invalid_creds(const struct cred *cred, const char *file, unsigned line)
877 pr_err("Invalid credentials\n");
878 pr_err("At %s:%u\n", file, line);
879 dump_invalid_creds(cred, "Specified", current);
882 EXPORT_SYMBOL(__invalid_creds);
885 * check the credentials on a process
887 void __validate_process_creds(struct task_struct *tsk,
888 const char *file, unsigned line)
890 if (tsk->cred == tsk->real_cred) {
891 if (unlikely(read_cred_subscribers(tsk->cred) < 2 ||
892 creds_are_invalid(tsk->cred)))
895 if (unlikely(read_cred_subscribers(tsk->real_cred) < 1 ||
896 read_cred_subscribers(tsk->cred) < 1 ||
897 creds_are_invalid(tsk->real_cred) ||
898 creds_are_invalid(tsk->cred)))
904 pr_err("Invalid process credentials\n");
905 pr_err("At %s:%u\n", file, line);
907 dump_invalid_creds(tsk->real_cred, "Real", tsk);
908 if (tsk->cred != tsk->real_cred)
909 dump_invalid_creds(tsk->cred, "Effective", tsk);
911 pr_err("Effective creds == Real creds\n");
914 EXPORT_SYMBOL(__validate_process_creds);
917 * check creds for do_exit()
919 void validate_creds_for_do_exit(struct task_struct *tsk)
921 kdebug("validate_creds_for_do_exit(%p,%p{%d,%d})",
922 tsk->real_cred, tsk->cred,
923 atomic_read(&tsk->cred->usage),
924 read_cred_subscribers(tsk->cred));
926 __validate_process_creds(tsk, __FILE__, __LINE__);
929 #endif /* CONFIG_DEBUG_CREDENTIALS */