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)
7 #include <linux/export.h>
8 #include <linux/cred.h>
9 #include <linux/slab.h>
10 #include <linux/sched.h>
11 #include <linux/sched/coredump.h>
12 #include <linux/key.h>
13 #include <linux/keyctl.h>
14 #include <linux/init_task.h>
15 #include <linux/security.h>
16 #include <linux/binfmts.h>
17 #include <linux/cn_proc.h>
18 #include <linux/uidgid.h>
21 #define kdebug(FMT, ...) \
22 printk("[%-5.5s%5u] " FMT "\n", \
23 current->comm, current->pid, ##__VA_ARGS__)
25 #define kdebug(FMT, ...) \
28 no_printk("[%-5.5s%5u] " FMT "\n", \
29 current->comm, current->pid, ##__VA_ARGS__); \
33 static struct kmem_cache
*cred_jar
;
35 /* init to 2 - one for init_task, one to ensure it is never freed */
36 static struct group_info init_groups
= { .usage
= ATOMIC_INIT(2) };
39 * The initial credentials for the initial task
41 struct cred init_cred
= {
42 .usage
= ATOMIC_INIT(4),
43 #ifdef CONFIG_DEBUG_CREDENTIALS
44 .subscribers
= ATOMIC_INIT(2),
47 .uid
= GLOBAL_ROOT_UID
,
48 .gid
= GLOBAL_ROOT_GID
,
49 .suid
= GLOBAL_ROOT_UID
,
50 .sgid
= GLOBAL_ROOT_GID
,
51 .euid
= GLOBAL_ROOT_UID
,
52 .egid
= GLOBAL_ROOT_GID
,
53 .fsuid
= GLOBAL_ROOT_UID
,
54 .fsgid
= GLOBAL_ROOT_GID
,
55 .securebits
= SECUREBITS_DEFAULT
,
56 .cap_inheritable
= CAP_EMPTY_SET
,
57 .cap_permitted
= CAP_FULL_SET
,
58 .cap_effective
= CAP_FULL_SET
,
59 .cap_bset
= CAP_FULL_SET
,
61 .user_ns
= &init_user_ns
,
62 .group_info
= &init_groups
,
63 .ucounts
= &init_ucounts
,
66 static inline void set_cred_subscribers(struct cred
*cred
, int n
)
68 #ifdef CONFIG_DEBUG_CREDENTIALS
69 atomic_set(&cred
->subscribers
, n
);
73 static inline int read_cred_subscribers(const struct cred
*cred
)
75 #ifdef CONFIG_DEBUG_CREDENTIALS
76 return atomic_read(&cred
->subscribers
);
82 static inline void alter_cred_subscribers(const struct cred
*_cred
, int n
)
84 #ifdef CONFIG_DEBUG_CREDENTIALS
85 struct cred
*cred
= (struct cred
*) _cred
;
87 atomic_add(n
, &cred
->subscribers
);
92 * The RCU callback to actually dispose of a set of credentials
94 static void put_cred_rcu(struct rcu_head
*rcu
)
96 struct cred
*cred
= container_of(rcu
, struct cred
, rcu
);
98 kdebug("put_cred_rcu(%p)", cred
);
100 #ifdef CONFIG_DEBUG_CREDENTIALS
101 if (cred
->magic
!= CRED_MAGIC_DEAD
||
102 atomic_read(&cred
->usage
) != 0 ||
103 read_cred_subscribers(cred
) != 0)
104 panic("CRED: put_cred_rcu() sees %p with"
105 " mag %x, put %p, usage %d, subscr %d\n",
106 cred
, cred
->magic
, cred
->put_addr
,
107 atomic_read(&cred
->usage
),
108 read_cred_subscribers(cred
));
110 if (atomic_read(&cred
->usage
) != 0)
111 panic("CRED: put_cred_rcu() sees %p with usage %d\n",
112 cred
, atomic_read(&cred
->usage
));
115 security_cred_free(cred
);
116 key_put(cred
->session_keyring
);
117 key_put(cred
->process_keyring
);
118 key_put(cred
->thread_keyring
);
119 key_put(cred
->request_key_auth
);
120 if (cred
->group_info
)
121 put_group_info(cred
->group_info
);
122 free_uid(cred
->user
);
124 put_ucounts(cred
->ucounts
);
125 put_user_ns(cred
->user_ns
);
126 kmem_cache_free(cred_jar
, cred
);
130 * __put_cred - Destroy a set of credentials
131 * @cred: The record to release
133 * Destroy a set of credentials on which no references remain.
135 void __put_cred(struct cred
*cred
)
137 kdebug("__put_cred(%p{%d,%d})", cred
,
138 atomic_read(&cred
->usage
),
139 read_cred_subscribers(cred
));
141 BUG_ON(atomic_read(&cred
->usage
) != 0);
142 #ifdef CONFIG_DEBUG_CREDENTIALS
143 BUG_ON(read_cred_subscribers(cred
) != 0);
144 cred
->magic
= CRED_MAGIC_DEAD
;
145 cred
->put_addr
= __builtin_return_address(0);
147 BUG_ON(cred
== current
->cred
);
148 BUG_ON(cred
== current
->real_cred
);
151 put_cred_rcu(&cred
->rcu
);
153 call_rcu(&cred
->rcu
, put_cred_rcu
);
155 EXPORT_SYMBOL(__put_cred
);
158 * Clean up a task's credentials when it exits
160 void exit_creds(struct task_struct
*tsk
)
164 kdebug("exit_creds(%u,%p,%p,{%d,%d})", tsk
->pid
, tsk
->real_cred
, tsk
->cred
,
165 atomic_read(&tsk
->cred
->usage
),
166 read_cred_subscribers(tsk
->cred
));
168 cred
= (struct cred
*) tsk
->real_cred
;
169 tsk
->real_cred
= NULL
;
170 validate_creds(cred
);
171 alter_cred_subscribers(cred
, -1);
174 cred
= (struct cred
*) tsk
->cred
;
176 validate_creds(cred
);
177 alter_cred_subscribers(cred
, -1);
180 #ifdef CONFIG_KEYS_REQUEST_CACHE
181 key_put(tsk
->cached_requested_key
);
182 tsk
->cached_requested_key
= NULL
;
187 * get_task_cred - Get another task's objective credentials
188 * @task: The task to query
190 * Get the objective credentials of a task, pinning them so that they can't go
191 * away. Accessing a task's credentials directly is not permitted.
193 * The caller must also make sure task doesn't get deleted, either by holding a
194 * ref on task or by holding tasklist_lock to prevent it from being unlinked.
196 const struct cred
*get_task_cred(struct task_struct
*task
)
198 const struct cred
*cred
;
203 cred
= __task_cred((task
));
205 } while (!get_cred_rcu(cred
));
210 EXPORT_SYMBOL(get_task_cred
);
213 * Allocate blank credentials, such that the credentials can be filled in at a
214 * later date without risk of ENOMEM.
216 struct cred
*cred_alloc_blank(void)
220 new = kmem_cache_zalloc(cred_jar
, GFP_KERNEL
);
224 atomic_set(&new->usage
, 1);
225 #ifdef CONFIG_DEBUG_CREDENTIALS
226 new->magic
= CRED_MAGIC
;
228 new->ucounts
= get_ucounts(&init_ucounts
);
230 if (security_cred_alloc_blank(new, GFP_KERNEL_ACCOUNT
) < 0)
241 * prepare_creds - Prepare a new set of credentials for modification
243 * Prepare a new set of task credentials for modification. A task's creds
244 * shouldn't generally be modified directly, therefore this function is used to
245 * prepare a new copy, which the caller then modifies and then commits by
246 * calling commit_creds().
248 * Preparation involves making a copy of the objective creds for modification.
250 * Returns a pointer to the new creds-to-be if successful, NULL otherwise.
252 * Call commit_creds() or abort_creds() to clean up.
254 struct cred
*prepare_creds(void)
256 struct task_struct
*task
= current
;
257 const struct cred
*old
;
260 validate_process_creds();
262 new = kmem_cache_alloc(cred_jar
, GFP_KERNEL
);
266 kdebug("prepare_creds() alloc %p", new);
269 memcpy(new, old
, sizeof(struct cred
));
272 atomic_set(&new->usage
, 1);
273 set_cred_subscribers(new, 0);
274 get_group_info(new->group_info
);
276 get_user_ns(new->user_ns
);
279 key_get(new->session_keyring
);
280 key_get(new->process_keyring
);
281 key_get(new->thread_keyring
);
282 key_get(new->request_key_auth
);
285 #ifdef CONFIG_SECURITY
286 new->security
= NULL
;
289 new->ucounts
= get_ucounts(new->ucounts
);
293 if (security_prepare_creds(new, old
, GFP_KERNEL_ACCOUNT
) < 0)
303 EXPORT_SYMBOL(prepare_creds
);
306 * Prepare credentials for current to perform an execve()
307 * - The caller must hold ->cred_guard_mutex
309 struct cred
*prepare_exec_creds(void)
313 new = prepare_creds();
318 /* newly exec'd tasks don't get a thread keyring */
319 key_put(new->thread_keyring
);
320 new->thread_keyring
= NULL
;
322 /* inherit the session keyring; new process keyring */
323 key_put(new->process_keyring
);
324 new->process_keyring
= NULL
;
327 new->suid
= new->fsuid
= new->euid
;
328 new->sgid
= new->fsgid
= new->egid
;
334 * Copy credentials for the new process created by fork()
336 * We share if we can, but under some circumstances we have to generate a new
339 * The new process gets the current process's subjective credentials as its
340 * objective and subjective credentials
342 int copy_creds(struct task_struct
*p
, unsigned long clone_flags
)
347 #ifdef CONFIG_KEYS_REQUEST_CACHE
348 p
->cached_requested_key
= NULL
;
353 !p
->cred
->thread_keyring
&&
355 clone_flags
& CLONE_THREAD
357 p
->real_cred
= get_cred(p
->cred
);
359 alter_cred_subscribers(p
->cred
, 2);
360 kdebug("share_creds(%p{%d,%d})",
361 p
->cred
, atomic_read(&p
->cred
->usage
),
362 read_cred_subscribers(p
->cred
));
363 inc_rlimit_ucounts(task_ucounts(p
), UCOUNT_RLIMIT_NPROC
, 1);
367 new = prepare_creds();
371 if (clone_flags
& CLONE_NEWUSER
) {
372 ret
= create_user_ns(new);
375 ret
= set_cred_ucounts(new);
381 /* new threads get their own thread keyrings if their parent already
383 if (new->thread_keyring
) {
384 key_put(new->thread_keyring
);
385 new->thread_keyring
= NULL
;
386 if (clone_flags
& CLONE_THREAD
)
387 install_thread_keyring_to_cred(new);
390 /* The process keyring is only shared between the threads in a process;
391 * anything outside of those threads doesn't inherit.
393 if (!(clone_flags
& CLONE_THREAD
)) {
394 key_put(new->process_keyring
);
395 new->process_keyring
= NULL
;
399 p
->cred
= p
->real_cred
= get_cred(new);
400 inc_rlimit_ucounts(task_ucounts(p
), UCOUNT_RLIMIT_NPROC
, 1);
401 alter_cred_subscribers(new, 2);
410 static bool cred_cap_issubset(const struct cred
*set
, const struct cred
*subset
)
412 const struct user_namespace
*set_ns
= set
->user_ns
;
413 const struct user_namespace
*subset_ns
= subset
->user_ns
;
415 /* If the two credentials are in the same user namespace see if
416 * the capabilities of subset are a subset of set.
418 if (set_ns
== subset_ns
)
419 return cap_issubset(subset
->cap_permitted
, set
->cap_permitted
);
421 /* The credentials are in a different user namespaces
422 * therefore one is a subset of the other only if a set is an
423 * ancestor of subset and set->euid is owner of subset or one
424 * of subsets ancestors.
426 for (;subset_ns
!= &init_user_ns
; subset_ns
= subset_ns
->parent
) {
427 if ((set_ns
== subset_ns
->parent
) &&
428 uid_eq(subset_ns
->owner
, set
->euid
))
436 * commit_creds - Install new credentials upon the current task
437 * @new: The credentials to be assigned
439 * Install a new set of credentials to the current task, using RCU to replace
440 * the old set. Both the objective and the subjective credentials pointers are
441 * updated. This function may not be called if the subjective credentials are
442 * in an overridden state.
444 * This function eats the caller's reference to the new credentials.
446 * Always returns 0 thus allowing this function to be tail-called at the end
447 * of, say, sys_setgid().
449 int commit_creds(struct cred
*new)
451 struct task_struct
*task
= current
;
452 const struct cred
*old
= task
->real_cred
;
454 kdebug("commit_creds(%p{%d,%d})", new,
455 atomic_read(&new->usage
),
456 read_cred_subscribers(new));
458 BUG_ON(task
->cred
!= old
);
459 #ifdef CONFIG_DEBUG_CREDENTIALS
460 BUG_ON(read_cred_subscribers(old
) < 2);
464 BUG_ON(atomic_read(&new->usage
) < 1);
466 get_cred(new); /* we will require a ref for the subj creds too */
468 /* dumpability changes */
469 if (!uid_eq(old
->euid
, new->euid
) ||
470 !gid_eq(old
->egid
, new->egid
) ||
471 !uid_eq(old
->fsuid
, new->fsuid
) ||
472 !gid_eq(old
->fsgid
, new->fsgid
) ||
473 !cred_cap_issubset(old
, new)) {
475 set_dumpable(task
->mm
, suid_dumpable
);
476 task
->pdeath_signal
= 0;
478 * If a task drops privileges and becomes nondumpable,
479 * the dumpability change must become visible before
480 * the credential change; otherwise, a __ptrace_may_access()
481 * racing with this change may be able to attach to a task it
482 * shouldn't be able to attach to (as if the task had dropped
483 * privileges without becoming nondumpable).
484 * Pairs with a read barrier in __ptrace_may_access().
489 /* alter the thread keyring */
490 if (!uid_eq(new->fsuid
, old
->fsuid
))
491 key_fsuid_changed(new);
492 if (!gid_eq(new->fsgid
, old
->fsgid
))
493 key_fsgid_changed(new);
496 * RLIMIT_NPROC limits on user->processes have already been checked
499 alter_cred_subscribers(new, 2);
500 if (new->user
!= old
->user
|| new->user_ns
!= old
->user_ns
)
501 inc_rlimit_ucounts(new->ucounts
, UCOUNT_RLIMIT_NPROC
, 1);
502 rcu_assign_pointer(task
->real_cred
, new);
503 rcu_assign_pointer(task
->cred
, new);
504 if (new->user
!= old
->user
)
505 dec_rlimit_ucounts(old
->ucounts
, UCOUNT_RLIMIT_NPROC
, 1);
506 alter_cred_subscribers(old
, -2);
508 /* send notifications */
509 if (!uid_eq(new->uid
, old
->uid
) ||
510 !uid_eq(new->euid
, old
->euid
) ||
511 !uid_eq(new->suid
, old
->suid
) ||
512 !uid_eq(new->fsuid
, old
->fsuid
))
513 proc_id_connector(task
, PROC_EVENT_UID
);
515 if (!gid_eq(new->gid
, old
->gid
) ||
516 !gid_eq(new->egid
, old
->egid
) ||
517 !gid_eq(new->sgid
, old
->sgid
) ||
518 !gid_eq(new->fsgid
, old
->fsgid
))
519 proc_id_connector(task
, PROC_EVENT_GID
);
521 /* release the old obj and subj refs both */
526 EXPORT_SYMBOL(commit_creds
);
529 * abort_creds - Discard a set of credentials and unlock the current task
530 * @new: The credentials that were going to be applied
532 * Discard a set of credentials that were under construction and unlock the
535 void abort_creds(struct cred
*new)
537 kdebug("abort_creds(%p{%d,%d})", new,
538 atomic_read(&new->usage
),
539 read_cred_subscribers(new));
541 #ifdef CONFIG_DEBUG_CREDENTIALS
542 BUG_ON(read_cred_subscribers(new) != 0);
544 BUG_ON(atomic_read(&new->usage
) < 1);
547 EXPORT_SYMBOL(abort_creds
);
550 * override_creds - Override the current process's subjective credentials
551 * @new: The credentials to be assigned
553 * Install a set of temporary override subjective credentials on the current
554 * process, returning the old set for later reversion.
556 const struct cred
*override_creds(const struct cred
*new)
558 const struct cred
*old
= current
->cred
;
560 kdebug("override_creds(%p{%d,%d})", new,
561 atomic_read(&new->usage
),
562 read_cred_subscribers(new));
568 * NOTE! This uses 'get_new_cred()' rather than 'get_cred()'.
570 * That means that we do not clear the 'non_rcu' flag, since
571 * we are only installing the cred into the thread-synchronous
572 * '->cred' pointer, not the '->real_cred' pointer that is
573 * visible to other threads under RCU.
575 * Also note that we did validate_creds() manually, not depending
576 * on the validation in 'get_cred()'.
578 get_new_cred((struct cred
*)new);
579 alter_cred_subscribers(new, 1);
580 rcu_assign_pointer(current
->cred
, new);
581 alter_cred_subscribers(old
, -1);
583 kdebug("override_creds() = %p{%d,%d}", old
,
584 atomic_read(&old
->usage
),
585 read_cred_subscribers(old
));
588 EXPORT_SYMBOL(override_creds
);
591 * revert_creds - Revert a temporary subjective credentials override
592 * @old: The credentials to be restored
594 * Revert a temporary set of override subjective credentials to an old set,
595 * discarding the override set.
597 void revert_creds(const struct cred
*old
)
599 const struct cred
*override
= current
->cred
;
601 kdebug("revert_creds(%p{%d,%d})", old
,
602 atomic_read(&old
->usage
),
603 read_cred_subscribers(old
));
606 validate_creds(override
);
607 alter_cred_subscribers(old
, 1);
608 rcu_assign_pointer(current
->cred
, old
);
609 alter_cred_subscribers(override
, -1);
612 EXPORT_SYMBOL(revert_creds
);
615 * cred_fscmp - Compare two credentials with respect to filesystem access.
616 * @a: The first credential
617 * @b: The second credential
619 * cred_cmp() will return zero if both credentials have the same
620 * fsuid, fsgid, and supplementary groups. That is, if they will both
621 * provide the same access to files based on mode/uid/gid.
622 * If the credentials are different, then either -1 or 1 will
623 * be returned depending on whether @a comes before or after @b
624 * respectively in an arbitrary, but stable, ordering of credentials.
626 * Return: -1, 0, or 1 depending on comparison
628 int cred_fscmp(const struct cred
*a
, const struct cred
*b
)
630 struct group_info
*ga
, *gb
;
635 if (uid_lt(a
->fsuid
, b
->fsuid
))
637 if (uid_gt(a
->fsuid
, b
->fsuid
))
640 if (gid_lt(a
->fsgid
, b
->fsgid
))
642 if (gid_gt(a
->fsgid
, b
->fsgid
))
653 if (ga
->ngroups
< gb
->ngroups
)
655 if (ga
->ngroups
> gb
->ngroups
)
658 for (g
= 0; g
< ga
->ngroups
; g
++) {
659 if (gid_lt(ga
->gid
[g
], gb
->gid
[g
]))
661 if (gid_gt(ga
->gid
[g
], gb
->gid
[g
]))
666 EXPORT_SYMBOL(cred_fscmp
);
668 int set_cred_ucounts(struct cred
*new)
670 struct task_struct
*task
= current
;
671 const struct cred
*old
= task
->real_cred
;
672 struct ucounts
*old_ucounts
= new->ucounts
;
674 if (new->user
== old
->user
&& new->user_ns
== old
->user_ns
)
678 * This optimization is needed because alloc_ucounts() uses locks
681 if (old_ucounts
&& old_ucounts
->ns
== new->user_ns
&& uid_eq(old_ucounts
->uid
, new->euid
))
684 if (!(new->ucounts
= alloc_ucounts(new->user_ns
, new->euid
)))
688 put_ucounts(old_ucounts
);
694 * initialise the credentials stuff
696 void __init
cred_init(void)
698 /* allocate a slab in which we can store credentials */
699 cred_jar
= kmem_cache_create("cred_jar", sizeof(struct cred
), 0,
700 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
|SLAB_ACCOUNT
, NULL
);
704 * prepare_kernel_cred - Prepare a set of credentials for a kernel service
705 * @daemon: A userspace daemon to be used as a reference
707 * Prepare a set of credentials for a kernel service. This can then be used to
708 * override a task's own credentials so that work can be done on behalf of that
709 * task that requires a different subjective context.
711 * @daemon is used to provide a base for the security record, but can be NULL.
712 * If @daemon is supplied, then the security data will be derived from that;
713 * otherwise they'll be set to 0 and no groups, full capabilities and no keys.
715 * The caller may change these controls afterwards if desired.
717 * Returns the new credentials or NULL if out of memory.
719 struct cred
*prepare_kernel_cred(struct task_struct
*daemon
)
721 const struct cred
*old
;
724 new = kmem_cache_alloc(cred_jar
, GFP_KERNEL
);
728 kdebug("prepare_kernel_cred() alloc %p", new);
731 old
= get_task_cred(daemon
);
733 old
= get_cred(&init_cred
);
739 atomic_set(&new->usage
, 1);
740 set_cred_subscribers(new, 0);
742 get_user_ns(new->user_ns
);
743 get_group_info(new->group_info
);
746 new->session_keyring
= NULL
;
747 new->process_keyring
= NULL
;
748 new->thread_keyring
= NULL
;
749 new->request_key_auth
= NULL
;
750 new->jit_keyring
= KEY_REQKEY_DEFL_THREAD_KEYRING
;
753 #ifdef CONFIG_SECURITY
754 new->security
= NULL
;
756 new->ucounts
= get_ucounts(new->ucounts
);
760 if (security_prepare_creds(new, old
, GFP_KERNEL_ACCOUNT
) < 0)
772 EXPORT_SYMBOL(prepare_kernel_cred
);
775 * set_security_override - Set the security ID in a set of credentials
776 * @new: The credentials to alter
777 * @secid: The LSM security ID to set
779 * Set the LSM security ID in a set of credentials so that the subjective
780 * security is overridden when an alternative set of credentials is used.
782 int set_security_override(struct cred
*new, u32 secid
)
784 return security_kernel_act_as(new, secid
);
786 EXPORT_SYMBOL(set_security_override
);
789 * set_security_override_from_ctx - Set the security ID in a set of credentials
790 * @new: The credentials to alter
791 * @secctx: The LSM security context to generate the security ID from.
793 * Set the LSM security ID in a set of credentials so that the subjective
794 * security is overridden when an alternative set of credentials is used. The
795 * security ID is specified in string form as a security context to be
796 * interpreted by the LSM.
798 int set_security_override_from_ctx(struct cred
*new, const char *secctx
)
803 ret
= security_secctx_to_secid(secctx
, strlen(secctx
), &secid
);
807 return set_security_override(new, secid
);
809 EXPORT_SYMBOL(set_security_override_from_ctx
);
812 * set_create_files_as - Set the LSM file create context in a set of credentials
813 * @new: The credentials to alter
814 * @inode: The inode to take the context from
816 * Change the LSM file creation context in a set of credentials to be the same
817 * as the object context of the specified inode, so that the new inodes have
818 * the same MAC context as that inode.
820 int set_create_files_as(struct cred
*new, struct inode
*inode
)
822 if (!uid_valid(inode
->i_uid
) || !gid_valid(inode
->i_gid
))
824 new->fsuid
= inode
->i_uid
;
825 new->fsgid
= inode
->i_gid
;
826 return security_kernel_create_files_as(new, inode
);
828 EXPORT_SYMBOL(set_create_files_as
);
830 #ifdef CONFIG_DEBUG_CREDENTIALS
832 bool creds_are_invalid(const struct cred
*cred
)
834 if (cred
->magic
!= CRED_MAGIC
)
838 EXPORT_SYMBOL(creds_are_invalid
);
841 * dump invalid credentials
843 static void dump_invalid_creds(const struct cred
*cred
, const char *label
,
844 const struct task_struct
*tsk
)
846 printk(KERN_ERR
"CRED: %s credentials: %p %s%s%s\n",
848 cred
== &init_cred
? "[init]" : "",
849 cred
== tsk
->real_cred
? "[real]" : "",
850 cred
== tsk
->cred
? "[eff]" : "");
851 printk(KERN_ERR
"CRED: ->magic=%x, put_addr=%p\n",
852 cred
->magic
, cred
->put_addr
);
853 printk(KERN_ERR
"CRED: ->usage=%d, subscr=%d\n",
854 atomic_read(&cred
->usage
),
855 read_cred_subscribers(cred
));
856 printk(KERN_ERR
"CRED: ->*uid = { %d,%d,%d,%d }\n",
857 from_kuid_munged(&init_user_ns
, cred
->uid
),
858 from_kuid_munged(&init_user_ns
, cred
->euid
),
859 from_kuid_munged(&init_user_ns
, cred
->suid
),
860 from_kuid_munged(&init_user_ns
, cred
->fsuid
));
861 printk(KERN_ERR
"CRED: ->*gid = { %d,%d,%d,%d }\n",
862 from_kgid_munged(&init_user_ns
, cred
->gid
),
863 from_kgid_munged(&init_user_ns
, cred
->egid
),
864 from_kgid_munged(&init_user_ns
, cred
->sgid
),
865 from_kgid_munged(&init_user_ns
, cred
->fsgid
));
866 #ifdef CONFIG_SECURITY
867 printk(KERN_ERR
"CRED: ->security is %p\n", cred
->security
);
868 if ((unsigned long) cred
->security
>= PAGE_SIZE
&&
869 (((unsigned long) cred
->security
& 0xffffff00) !=
870 (POISON_FREE
<< 24 | POISON_FREE
<< 16 | POISON_FREE
<< 8)))
871 printk(KERN_ERR
"CRED: ->security {%x, %x}\n",
872 ((u32
*)cred
->security
)[0],
873 ((u32
*)cred
->security
)[1]);
878 * report use of invalid credentials
880 void __invalid_creds(const struct cred
*cred
, const char *file
, unsigned line
)
882 printk(KERN_ERR
"CRED: Invalid credentials\n");
883 printk(KERN_ERR
"CRED: At %s:%u\n", file
, line
);
884 dump_invalid_creds(cred
, "Specified", current
);
887 EXPORT_SYMBOL(__invalid_creds
);
890 * check the credentials on a process
892 void __validate_process_creds(struct task_struct
*tsk
,
893 const char *file
, unsigned line
)
895 if (tsk
->cred
== tsk
->real_cred
) {
896 if (unlikely(read_cred_subscribers(tsk
->cred
) < 2 ||
897 creds_are_invalid(tsk
->cred
)))
900 if (unlikely(read_cred_subscribers(tsk
->real_cred
) < 1 ||
901 read_cred_subscribers(tsk
->cred
) < 1 ||
902 creds_are_invalid(tsk
->real_cred
) ||
903 creds_are_invalid(tsk
->cred
)))
909 printk(KERN_ERR
"CRED: Invalid process credentials\n");
910 printk(KERN_ERR
"CRED: At %s:%u\n", file
, line
);
912 dump_invalid_creds(tsk
->real_cred
, "Real", tsk
);
913 if (tsk
->cred
!= tsk
->real_cred
)
914 dump_invalid_creds(tsk
->cred
, "Effective", tsk
);
916 printk(KERN_ERR
"CRED: Effective creds == Real creds\n");
919 EXPORT_SYMBOL(__validate_process_creds
);
922 * check creds for do_exit()
924 void validate_creds_for_do_exit(struct task_struct
*tsk
)
926 kdebug("validate_creds_for_do_exit(%p,%p{%d,%d})",
927 tsk
->real_cred
, tsk
->cred
,
928 atomic_read(&tsk
->cred
->usage
),
929 read_cred_subscribers(tsk
->cred
));
931 __validate_process_creds(tsk
, __FILE__
, __LINE__
);
934 #endif /* CONFIG_DEBUG_CREDENTIALS */