-/* Task credentials management - see Documentation/credentials.txt
+/* Task credentials management - see Documentation/security/credentials.txt
*
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/cred.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/keyctl.h>
#include <linux/init_task.h>
#include <linux/security.h>
+#include <linux/binfmts.h>
#include <linux/cn_proc.h>
-#include "cred-internals.h"
#if 0
#define kdebug(FMT, ...) \
printk("[%-5.5s%5u] "FMT"\n", current->comm, current->pid ,##__VA_ARGS__)
#else
-static inline __attribute__((format(printf, 1, 2)))
-void no_printk(const char *fmt, ...)
-{
-}
#define kdebug(FMT, ...) \
no_printk("[%-5.5s%5u] "FMT"\n", current->comm, current->pid ,##__VA_ARGS__)
#endif
static struct thread_group_cred init_tgcred = {
.usage = ATOMIC_INIT(2),
.tgid = 0,
- .lock = SPIN_LOCK_UNLOCKED,
+ .lock = __SPIN_LOCK_UNLOCKED(init_cred.tgcred.lock),
};
#endif
.magic = CRED_MAGIC,
#endif
.securebits = SECUREBITS_DEFAULT,
- .cap_inheritable = CAP_INIT_INH_SET,
+ .cap_inheritable = CAP_EMPTY_SET,
.cap_permitted = CAP_FULL_SET,
- .cap_effective = CAP_INIT_EFF_SET,
- .cap_bset = CAP_INIT_BSET,
+ .cap_effective = CAP_FULL_SET,
+ .cap_bset = CAP_FULL_SET,
.user = INIT_USER,
+ .user_ns = &init_user_ns,
.group_info = &init_groups,
#ifdef CONFIG_KEYS
.tgcred = &init_tgcred,
}
}
+/**
+ * get_task_cred - Get another task's objective credentials
+ * @task: The task to query
+ *
+ * Get the objective credentials of a task, pinning them so that they can't go
+ * away. Accessing a task's credentials directly is not permitted.
+ *
+ * The caller must also make sure task doesn't get deleted, either by holding a
+ * ref on task or by holding tasklist_lock to prevent it from being unlinked.
+ */
+const struct cred *get_task_cred(struct task_struct *task)
+{
+ const struct cred *cred;
+
+ rcu_read_lock();
+
+ do {
+ cred = __task_cred((task));
+ BUG_ON(!cred);
+ } while (!atomic_inc_not_zero(&((struct cred *)cred)->usage));
+
+ rcu_read_unlock();
+ return cred;
+}
+
/*
* Allocate blank credentials, such that the credentials can be filled in at a
* later date without risk of ENOMEM.
#endif
atomic_set(&new->usage, 1);
+#ifdef CONFIG_DEBUG_CREDENTIALS
+ new->magic = CRED_MAGIC;
+#endif
if (security_cred_alloc_blank(new, GFP_KERNEL) < 0)
goto error;
-#ifdef CONFIG_DEBUG_CREDENTIALS
- new->magic = CRED_MAGIC;
-#endif
return new;
error:
/*
* Prepare credentials for current to perform an execve()
- * - The caller must hold current->cred_guard_mutex
+ * - The caller must hold ->cred_guard_mutex
*/
struct cred *prepare_exec_creds(void)
{
return new;
}
-/*
- * prepare new credentials for the usermode helper dispatcher
- */
-struct cred *prepare_usermodehelper_creds(void)
-{
-#ifdef CONFIG_KEYS
- struct thread_group_cred *tgcred = NULL;
-#endif
- struct cred *new;
-
-#ifdef CONFIG_KEYS
- tgcred = kzalloc(sizeof(*new->tgcred), GFP_ATOMIC);
- if (!tgcred)
- return NULL;
-#endif
-
- new = kmem_cache_alloc(cred_jar, GFP_ATOMIC);
- if (!new)
- goto free_tgcred;
-
- kdebug("prepare_usermodehelper_creds() alloc %p", new);
-
- memcpy(new, &init_cred, sizeof(struct cred));
-
- atomic_set(&new->usage, 1);
- set_cred_subscribers(new, 0);
- get_group_info(new->group_info);
- get_uid(new->user);
-
-#ifdef CONFIG_KEYS
- new->thread_keyring = NULL;
- new->request_key_auth = NULL;
- new->jit_keyring = KEY_REQKEY_DEFL_DEFAULT;
-
- atomic_set(&tgcred->usage, 1);
- spin_lock_init(&tgcred->lock);
- new->tgcred = tgcred;
-#endif
-
-#ifdef CONFIG_SECURITY
- new->security = NULL;
-#endif
- if (security_prepare_creds(new, &init_cred, GFP_ATOMIC) < 0)
- goto error;
- validate_creds(new);
-
- BUG_ON(atomic_read(&new->usage) != 1);
- return new;
-
-error:
- put_cred(new);
- return NULL;
-
-free_tgcred:
-#ifdef CONFIG_KEYS
- kfree(tgcred);
-#endif
- return NULL;
-}
-
/*
* Copy credentials for the new process created by fork()
*
struct cred *new;
int ret;
- mutex_init(&p->cred_guard_mutex);
+ p->replacement_session_keyring = NULL;
if (
#ifdef CONFIG_KEYS
goto error_put;
}
+ /* cache user_ns in cred. Doesn't need a refcount because it will
+ * stay pinned by cred->user
+ */
+ new->user_ns = new->user->user_ns;
+
#ifdef CONFIG_KEYS
/* new threads get their own thread keyrings if their parent already
* had one */
#endif
BUG_ON(atomic_read(&new->usage) < 1);
- security_commit_creds(new, old);
-
get_cred(new); /* we will require a ref for the subj creds too */
/* dumpability changes */
key_fsgid_changed(task);
/* do it
- * - What if a process setreuid()'s and this brings the
- * new uid over his NPROC rlimit? We can check this now
- * cheaply with the new uid cache, so if it matters
- * we should be checking for it. -DaveM
+ * RLIMIT_NPROC limits on user->processes have already been checked
+ * in set_user().
*/
alter_cred_subscribers(new, 2);
if (new->user != old->user)
atomic_dec(&old->user->processes);
alter_cred_subscribers(old, -2);
- sched_switch_user(task);
-
/* send notifications */
if (new->uid != old->uid ||
new->euid != old->euid ||
*/
struct cred *prepare_kernel_cred(struct task_struct *daemon)
{
+#ifdef CONFIG_KEYS
+ struct thread_group_cred *tgcred;
+#endif
const struct cred *old;
struct cred *new;
if (!new)
return NULL;
+#ifdef CONFIG_KEYS
+ tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL);
+ if (!tgcred) {
+ kmem_cache_free(cred_jar, new);
+ return NULL;
+ }
+#endif
+
kdebug("prepare_kernel_cred() alloc %p", new);
if (daemon)
validate_creds(old);
*new = *old;
+ atomic_set(&new->usage, 1);
+ set_cred_subscribers(new, 0);
get_uid(new->user);
get_group_info(new->group_info);
#ifdef CONFIG_KEYS
- atomic_inc(&init_tgcred.usage);
- new->tgcred = &init_tgcred;
+ atomic_set(&tgcred->usage, 1);
+ spin_lock_init(&tgcred->lock);
+ tgcred->process_keyring = NULL;
+ tgcred->session_keyring = NULL;
+ new->tgcred = tgcred;
new->request_key_auth = NULL;
new->thread_keyring = NULL;
new->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
if (security_prepare_creds(new, old, GFP_KERNEL) < 0)
goto error;
- atomic_set(&new->usage, 1);
- set_cred_subscribers(new, 0);
put_cred(old);
validate_creds(new);
return new;
{
if (cred->magic != CRED_MAGIC)
return true;
- if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers))
- return true;
#ifdef CONFIG_SECURITY_SELINUX
- if (selinux_is_enabled()) {
+ /*
+ * cred->security == NULL if security_cred_alloc_blank() or
+ * security_prepare_creds() returned an error.
+ */
+ if (selinux_is_enabled() && cred->security) {
if ((unsigned long) cred->security < PAGE_SIZE)
return true;
if ((*(u32 *)cred->security & 0xffffff00) ==
Code Review / linux-2.6.git / blobdiff