-/* process_keys.c: management of a process's keyrings
+/* Management of a process's keyrings
*
- * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
#include <linux/keyctl.h>
#include <linux/fs.h>
#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/user_namespace.h>
#include <asm/uaccess.h>
#include "internal.h"
/* session keyring create vs join semaphore */
-static DECLARE_MUTEX(key_session_sem);
+static DEFINE_MUTEX(key_session_mutex);
+
+/* user keyring creation semaphore */
+static DEFINE_MUTEX(key_user_keyring_mutex);
/* the root user's tracking struct */
struct key_user root_key_user = {
.usage = ATOMIC_INIT(3),
- .consq = LIST_HEAD_INIT(root_key_user.consq),
- .lock = SPIN_LOCK_UNLOCKED,
+ .cons_lock = __MUTEX_INITIALIZER(root_key_user.cons_lock),
+ .lock = __SPIN_LOCK_UNLOCKED(root_key_user.lock),
.nkeys = ATOMIC_INIT(2),
.nikeys = ATOMIC_INIT(2),
.uid = 0,
-};
-
-/* the root user's UID keyring */
-struct key root_user_keyring = {
- .usage = ATOMIC_INIT(1),
- .serial = 2,
- .type = &key_type_keyring,
- .user = &root_key_user,
- .sem = __RWSEM_INITIALIZER(root_user_keyring.sem),
- .perm = KEY_USR_ALL,
- .flags = 1 << KEY_FLAG_INSTANTIATED,
- .description = "_uid.0",
-#ifdef KEY_DEBUGGING
- .magic = KEY_DEBUG_MAGIC,
-#endif
-};
-
-/* the root user's default session keyring */
-struct key root_session_keyring = {
- .usage = ATOMIC_INIT(1),
- .serial = 1,
- .type = &key_type_keyring,
- .user = &root_key_user,
- .sem = __RWSEM_INITIALIZER(root_session_keyring.sem),
- .perm = KEY_USR_ALL,
- .flags = 1 << KEY_FLAG_INSTANTIATED,
- .description = "_uid_ses.0",
-#ifdef KEY_DEBUGGING
- .magic = KEY_DEBUG_MAGIC,
-#endif
+ .user_ns = &init_user_ns,
};
/*****************************************************************************/
/*
- * allocate the keyrings to be associated with a UID
+ * install user and user session keyrings for a particular UID
*/
-int alloc_uid_keyring(struct user_struct *user)
+int install_user_keyrings(void)
{
+ struct user_struct *user;
+ const struct cred *cred;
struct key *uid_keyring, *session_keyring;
char buf[20];
int ret;
- /* concoct a default session keyring */
- sprintf(buf, "_uid_ses.%u", user->uid);
+ cred = current_cred();
+ user = cred->user;
- session_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, 0, NULL);
- if (IS_ERR(session_keyring)) {
- ret = PTR_ERR(session_keyring);
- goto error;
+ kenter("%p{%u}", user, user->uid);
+
+ if (user->uid_keyring) {
+ kleave(" = 0 [exist]");
+ return 0;
}
- /* and a UID specific keyring, pointed to by the default session
- * keyring */
- sprintf(buf, "_uid.%u", user->uid);
+ mutex_lock(&key_user_keyring_mutex);
+ ret = 0;
- uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1, 0,
- session_keyring);
- if (IS_ERR(uid_keyring)) {
- key_put(session_keyring);
- ret = PTR_ERR(uid_keyring);
- goto error;
+ if (!user->uid_keyring) {
+ /* get the UID-specific keyring
+ * - there may be one in existence already as it may have been
+ * pinned by a session, but the user_struct pointing to it
+ * may have been destroyed by setuid */
+ sprintf(buf, "_uid.%u", user->uid);
+
+ uid_keyring = find_keyring_by_name(buf, true);
+ if (IS_ERR(uid_keyring)) {
+ uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1,
+ cred, KEY_ALLOC_IN_QUOTA,
+ NULL);
+ if (IS_ERR(uid_keyring)) {
+ ret = PTR_ERR(uid_keyring);
+ goto error;
+ }
+ }
+
+ /* get a default session keyring (which might also exist
+ * already) */
+ sprintf(buf, "_uid_ses.%u", user->uid);
+
+ session_keyring = find_keyring_by_name(buf, true);
+ if (IS_ERR(session_keyring)) {
+ session_keyring =
+ keyring_alloc(buf, user->uid, (gid_t) -1,
+ cred, KEY_ALLOC_IN_QUOTA, NULL);
+ if (IS_ERR(session_keyring)) {
+ ret = PTR_ERR(session_keyring);
+ goto error_release;
+ }
+
+ /* we install a link from the user session keyring to
+ * the user keyring */
+ ret = key_link(session_keyring, uid_keyring);
+ if (ret < 0)
+ goto error_release_both;
+ }
+
+ /* install the keyrings */
+ user->uid_keyring = uid_keyring;
+ user->session_keyring = session_keyring;
}
- /* install the keyrings */
- user->uid_keyring = uid_keyring;
- user->session_keyring = session_keyring;
- ret = 0;
+ mutex_unlock(&key_user_keyring_mutex);
+ kleave(" = 0");
+ return 0;
- error:
+error_release_both:
+ key_put(session_keyring);
+error_release:
+ key_put(uid_keyring);
+error:
+ mutex_unlock(&key_user_keyring_mutex);
+ kleave(" = %d", ret);
return ret;
+}
-} /* end alloc_uid_keyring() */
-
-/*****************************************************************************/
/*
- * deal with the UID changing
+ * install a fresh thread keyring directly to new credentials
*/
-void switch_uid_keyring(struct user_struct *new_user)
+int install_thread_keyring_to_cred(struct cred *new)
{
-#if 0 /* do nothing for now */
- struct key *old;
-
- /* switch to the new user's session keyring if we were running under
- * root's default session keyring */
- if (new_user->uid != 0 &&
- current->session_keyring == &root_session_keyring
- ) {
- atomic_inc(&new_user->session_keyring->usage);
-
- task_lock(current);
- old = current->session_keyring;
- current->session_keyring = new_user->session_keyring;
- task_unlock(current);
+ struct key *keyring;
- key_put(old);
- }
-#endif
+ keyring = keyring_alloc("_tid", new->uid, new->gid, new,
+ KEY_ALLOC_QUOTA_OVERRUN, NULL);
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
-} /* end switch_uid_keyring() */
+ new->thread_keyring = keyring;
+ return 0;
+}
-/*****************************************************************************/
/*
* install a fresh thread keyring, discarding the old one
*/
-int install_thread_keyring(struct task_struct *tsk)
+static int install_thread_keyring(void)
{
- struct key *keyring, *old;
- char buf[20];
+ struct cred *new;
int ret;
- sprintf(buf, "_tid.%u", tsk->pid);
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
+ BUG_ON(new->thread_keyring);
+
+ ret = install_thread_keyring_to_cred(new);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret;
}
- task_lock(tsk);
- old = tsk->thread_keyring;
- tsk->thread_keyring = keyring;
- task_unlock(tsk);
+ return commit_creds(new);
+}
- ret = 0;
+/*
+ * install a process keyring directly to a credentials struct
+ * - returns -EEXIST if there was already a process keyring, 0 if one installed,
+ * and other -ve on any other error
+ */
+int install_process_keyring_to_cred(struct cred *new)
+{
+ struct key *keyring;
+ int ret;
- key_put(old);
- error:
+ if (new->tgcred->process_keyring)
+ return -EEXIST;
+
+ keyring = keyring_alloc("_pid", new->uid, new->gid,
+ new, KEY_ALLOC_QUOTA_OVERRUN, NULL);
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
+
+ spin_lock_irq(&new->tgcred->lock);
+ if (!new->tgcred->process_keyring) {
+ new->tgcred->process_keyring = keyring;
+ keyring = NULL;
+ ret = 0;
+ } else {
+ ret = -EEXIST;
+ }
+ spin_unlock_irq(&new->tgcred->lock);
+ key_put(keyring);
return ret;
+}
-} /* end install_thread_keyring() */
-
-/*****************************************************************************/
/*
* make sure a process keyring is installed
+ * - we
*/
-int install_process_keyring(struct task_struct *tsk)
+static int install_process_keyring(void)
{
- unsigned long flags;
- struct key *keyring;
- char buf[20];
+ struct cred *new;
int ret;
- if (!tsk->signal->process_keyring) {
- sprintf(buf, "_pid.%u", tsk->tgid);
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
- }
-
- /* attach keyring */
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
- if (!tsk->signal->process_keyring) {
- tsk->signal->process_keyring = keyring;
- keyring = NULL;
- }
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
-
- key_put(keyring);
+ ret = install_process_keyring_to_cred(new);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret != -EEXIST ?: 0;
}
- ret = 0;
- error:
- return ret;
-
-} /* end install_process_keyring() */
+ return commit_creds(new);
+}
-/*****************************************************************************/
/*
- * install a session keyring, discarding the old one
- * - if a keyring is not supplied, an empty one is invented
+ * install a session keyring directly to a credentials struct
*/
-static int install_session_keyring(struct task_struct *tsk,
- struct key *keyring)
+static int install_session_keyring_to_cred(struct cred *cred,
+ struct key *keyring)
{
unsigned long flags;
struct key *old;
- char buf[20];
- int ret;
+
+ might_sleep();
/* create an empty session keyring */
if (!keyring) {
- sprintf(buf, "_ses.%u", tsk->tgid);
-
- keyring = keyring_alloc(buf, tsk->uid, tsk->gid, 1, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
- }
- }
- else {
+ flags = KEY_ALLOC_QUOTA_OVERRUN;
+ if (cred->tgcred->session_keyring)
+ flags = KEY_ALLOC_IN_QUOTA;
+
+ keyring = keyring_alloc("_ses", cred->uid, cred->gid,
+ cred, flags, NULL);
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
+ } else {
atomic_inc(&keyring->usage);
}
/* install the keyring */
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
- old = rcu_dereference(tsk->signal->session_keyring);
- rcu_assign_pointer(tsk->signal->session_keyring, keyring);
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
-
- ret = 0;
-
- /* we're using RCU on the pointer */
- synchronize_rcu();
- key_put(old);
- error:
- return ret;
-
-} /* end install_session_keyring() */
-
-/*****************************************************************************/
-/*
- * copy the keys in a thread group for fork without CLONE_THREAD
- */
-int copy_thread_group_keys(struct task_struct *tsk)
-{
- key_check(current->thread_group->session_keyring);
- key_check(current->thread_group->process_keyring);
-
- /* no process keyring yet */
- tsk->signal->process_keyring = NULL;
-
- /* same session keyring */
- rcu_read_lock();
- tsk->signal->session_keyring =
- key_get(rcu_dereference(current->signal->session_keyring));
- rcu_read_unlock();
-
- return 0;
-
-} /* end copy_thread_group_keys() */
-
-/*****************************************************************************/
-/*
- * copy the keys for fork
- */
-int copy_keys(unsigned long clone_flags, struct task_struct *tsk)
-{
- key_check(tsk->thread_keyring);
+ spin_lock_irq(&cred->tgcred->lock);
+ old = cred->tgcred->session_keyring;
+ rcu_assign_pointer(cred->tgcred->session_keyring, keyring);
+ spin_unlock_irq(&cred->tgcred->lock);
+
+ /* we're using RCU on the pointer, but there's no point synchronising
+ * on it if it didn't previously point to anything */
+ if (old) {
+ synchronize_rcu();
+ key_put(old);
+ }
- /* no thread keyring yet */
- tsk->thread_keyring = NULL;
return 0;
+}
-} /* end copy_keys() */
-
-/*****************************************************************************/
-/*
- * dispose of thread group keys upon thread group destruction
- */
-void exit_thread_group_keys(struct signal_struct *tg)
-{
- key_put(tg->session_keyring);
- key_put(tg->process_keyring);
-
-} /* end exit_thread_group_keys() */
-
-/*****************************************************************************/
-/*
- * dispose of keys upon thread exit
- */
-void exit_keys(struct task_struct *tsk)
-{
- key_put(tsk->thread_keyring);
-
-} /* end exit_keys() */
-
-/*****************************************************************************/
/*
- * deal with execve()
+ * install a session keyring, discarding the old one
+ * - if a keyring is not supplied, an empty one is invented
*/
-int exec_keys(struct task_struct *tsk)
+static int install_session_keyring(struct key *keyring)
{
- unsigned long flags;
- struct key *old;
-
- /* newly exec'd tasks don't get a thread keyring */
- task_lock(tsk);
- old = tsk->thread_keyring;
- tsk->thread_keyring = NULL;
- task_unlock(tsk);
-
- key_put(old);
-
- /* discard the process keyring from a newly exec'd task */
- spin_lock_irqsave(&tsk->sighand->siglock, flags);
- old = tsk->signal->process_keyring;
- tsk->signal->process_keyring = NULL;
- spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
-
- key_put(old);
-
- return 0;
+ struct cred *new;
+ int ret;
-} /* end exec_keys() */
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
-/*****************************************************************************/
-/*
- * deal with SUID programs
- * - we might want to make this invent a new session keyring
- */
-int suid_keys(struct task_struct *tsk)
-{
- return 0;
+ ret = install_session_keyring_to_cred(new, NULL);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret;
+ }
-} /* end suid_keys() */
+ return commit_creds(new);
+}
/*****************************************************************************/
/*
void key_fsuid_changed(struct task_struct *tsk)
{
/* update the ownership of the thread keyring */
- if (tsk->thread_keyring) {
- down_write(&tsk->thread_keyring->sem);
- tsk->thread_keyring->uid = tsk->fsuid;
- up_write(&tsk->thread_keyring->sem);
+ BUG_ON(!tsk->cred);
+ if (tsk->cred->thread_keyring) {
+ down_write(&tsk->cred->thread_keyring->sem);
+ tsk->cred->thread_keyring->uid = tsk->cred->fsuid;
+ up_write(&tsk->cred->thread_keyring->sem);
}
} /* end key_fsuid_changed() */
void key_fsgid_changed(struct task_struct *tsk)
{
/* update the ownership of the thread keyring */
- if (tsk->thread_keyring) {
- down_write(&tsk->thread_keyring->sem);
- tsk->thread_keyring->gid = tsk->fsgid;
- up_write(&tsk->thread_keyring->sem);
+ BUG_ON(!tsk->cred);
+ if (tsk->cred->thread_keyring) {
+ down_write(&tsk->cred->thread_keyring->sem);
+ tsk->cred->thread_keyring->gid = tsk->cred->fsgid;
+ up_write(&tsk->cred->thread_keyring->sem);
}
} /* end key_fsgid_changed() */
* - we return -EAGAIN if we didn't find any matching key
* - we return -ENOKEY if we found only negative matching keys
*/
-struct key *search_process_keyrings(struct key_type *type,
- const void *description,
- key_match_func_t match,
- struct task_struct *context)
+key_ref_t search_process_keyrings(struct key_type *type,
+ const void *description,
+ key_match_func_t match,
+ const struct cred *cred)
{
struct request_key_auth *rka;
- struct key *key, *ret, *err, *instkey;
+ key_ref_t key_ref, ret, err;
+
+ might_sleep();
/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
* searchable, but we failed to find a key or we found a negative key;
*
* in terms of priority: success > -ENOKEY > -EAGAIN > other error
*/
- key = NULL;
+ key_ref = NULL;
ret = NULL;
err = ERR_PTR(-EAGAIN);
/* search the thread keyring first */
- if (context->thread_keyring) {
- key = keyring_search_aux(context->thread_keyring,
- context, type, description, match);
- if (!IS_ERR(key))
+ if (cred->thread_keyring) {
+ key_ref = keyring_search_aux(
+ make_key_ref(cred->thread_keyring, 1),
+ cred, type, description, match);
+ if (!IS_ERR(key_ref))
goto found;
- switch (PTR_ERR(key)) {
+ switch (PTR_ERR(key_ref)) {
case -EAGAIN: /* no key */
if (ret)
break;
case -ENOKEY: /* negative key */
- ret = key;
+ ret = key_ref;
break;
default:
- err = key;
+ err = key_ref;
break;
}
}
/* search the process keyring second */
- if (context->signal->process_keyring) {
- key = keyring_search_aux(context->signal->process_keyring,
- context, type, description, match);
- if (!IS_ERR(key))
+ if (cred->tgcred->process_keyring) {
+ key_ref = keyring_search_aux(
+ make_key_ref(cred->tgcred->process_keyring, 1),
+ cred, type, description, match);
+ if (!IS_ERR(key_ref))
goto found;
- switch (PTR_ERR(key)) {
+ switch (PTR_ERR(key_ref)) {
case -EAGAIN: /* no key */
if (ret)
break;
case -ENOKEY: /* negative key */
- ret = key;
+ ret = key_ref;
break;
default:
- err = key;
+ err = key_ref;
break;
}
}
/* search the session keyring */
- if (context->signal->session_keyring) {
+ if (cred->tgcred->session_keyring) {
rcu_read_lock();
- key = keyring_search_aux(
- rcu_dereference(context->signal->session_keyring),
- context, type, description, match);
+ key_ref = keyring_search_aux(
+ make_key_ref(rcu_dereference(
+ cred->tgcred->session_keyring),
+ 1),
+ cred, type, description, match);
rcu_read_unlock();
- if (!IS_ERR(key))
+ if (!IS_ERR(key_ref))
goto found;
- switch (PTR_ERR(key)) {
+ switch (PTR_ERR(key_ref)) {
case -EAGAIN: /* no key */
if (ret)
break;
case -ENOKEY: /* negative key */
- ret = key;
+ ret = key_ref;
break;
default:
- err = key;
+ err = key_ref;
break;
}
-
- /* if this process has a session keyring and that has an
- * instantiation authorisation key in the bottom level, then we
- * also search the keyrings of the process mentioned there */
- if (context != current)
- goto no_key;
-
- rcu_read_lock();
- instkey = __keyring_search_one(
- rcu_dereference(context->signal->session_keyring),
- &key_type_request_key_auth, NULL, 0);
- rcu_read_unlock();
-
- if (IS_ERR(instkey))
- goto no_key;
-
- rka = instkey->payload.data;
-
- key = search_process_keyrings(type, description, match,
- rka->context);
- key_put(instkey);
-
- if (!IS_ERR(key))
+ }
+ /* or search the user-session keyring */
+ else if (cred->user->session_keyring) {
+ key_ref = keyring_search_aux(
+ make_key_ref(cred->user->session_keyring, 1),
+ cred, type, description, match);
+ if (!IS_ERR(key_ref))
goto found;
- switch (PTR_ERR(key)) {
+ switch (PTR_ERR(key_ref)) {
case -EAGAIN: /* no key */
if (ret)
break;
case -ENOKEY: /* negative key */
- ret = key;
+ ret = key_ref;
break;
default:
- err = key;
+ err = key_ref;
break;
}
}
- /* or search the user-session keyring */
- else {
- key = keyring_search_aux(context->user->session_keyring,
- context, type, description, match);
- if (!IS_ERR(key))
- goto found;
- switch (PTR_ERR(key)) {
- case -EAGAIN: /* no key */
- if (ret)
+ /* if this process has an instantiation authorisation key, then we also
+ * search the keyrings of the process mentioned there
+ * - we don't permit access to request_key auth keys via this method
+ */
+ if (cred->request_key_auth &&
+ cred == current_cred() &&
+ type != &key_type_request_key_auth
+ ) {
+ /* defend against the auth key being revoked */
+ down_read(&cred->request_key_auth->sem);
+
+ if (key_validate(cred->request_key_auth) == 0) {
+ rka = cred->request_key_auth->payload.data;
+
+ key_ref = search_process_keyrings(type, description,
+ match, rka->cred);
+
+ up_read(&cred->request_key_auth->sem);
+
+ if (!IS_ERR(key_ref))
+ goto found;
+
+ switch (PTR_ERR(key_ref)) {
+ case -EAGAIN: /* no key */
+ if (ret)
+ break;
+ case -ENOKEY: /* negative key */
+ ret = key_ref;
break;
- case -ENOKEY: /* negative key */
- ret = key;
- break;
- default:
- err = key;
- break;
+ default:
+ err = key_ref;
+ break;
+ }
+ } else {
+ up_read(&cred->request_key_auth->sem);
}
}
-
-no_key:
/* no key - decide on the error we're going to go for */
- key = ret ? ret : err;
+ key_ref = ret ? ret : err;
found:
- return key;
+ return key_ref;
} /* end search_process_keyrings() */
/*****************************************************************************/
/*
+ * see if the key we're looking at is the target key
+ */
+static int lookup_user_key_possessed(const struct key *key, const void *target)
+{
+ return key == target;
+
+} /* end lookup_user_key_possessed() */
+
+/*****************************************************************************/
+/*
* lookup a key given a key ID from userspace with a given permissions mask
* - don't create special keyrings unless so requested
* - partially constructed keys aren't found unless requested
*/
-struct key *lookup_user_key(struct task_struct *context, key_serial_t id,
- int create, int partial, key_perm_t perm)
+key_ref_t lookup_user_key(key_serial_t id, int create, int partial,
+ key_perm_t perm)
{
+ struct request_key_auth *rka;
+ const struct cred *cred;
struct key *key;
+ key_ref_t key_ref, skey_ref;
int ret;
- if (!context)
- context = current;
-
- key = ERR_PTR(-ENOKEY);
+try_again:
+ cred = get_current_cred();
+ key_ref = ERR_PTR(-ENOKEY);
switch (id) {
case KEY_SPEC_THREAD_KEYRING:
- if (!context->thread_keyring) {
+ if (!cred->thread_keyring) {
if (!create)
goto error;
- ret = install_thread_keyring(context);
+ ret = install_thread_keyring();
if (ret < 0) {
key = ERR_PTR(ret);
goto error;
}
+ goto reget_creds;
}
- key = context->thread_keyring;
+ key = cred->thread_keyring;
atomic_inc(&key->usage);
+ key_ref = make_key_ref(key, 1);
break;
case KEY_SPEC_PROCESS_KEYRING:
- if (!context->signal->process_keyring) {
+ if (!cred->tgcred->process_keyring) {
if (!create)
goto error;
- ret = install_process_keyring(context);
+ ret = install_process_keyring();
if (ret < 0) {
key = ERR_PTR(ret);
goto error;
}
+ goto reget_creds;
}
- key = context->signal->process_keyring;
+ key = cred->tgcred->process_keyring;
atomic_inc(&key->usage);
+ key_ref = make_key_ref(key, 1);
break;
case KEY_SPEC_SESSION_KEYRING:
- if (!context->signal->session_keyring) {
+ if (!cred->tgcred->session_keyring) {
/* always install a session keyring upon access if one
* doesn't exist yet */
+ ret = install_user_keyrings();
+ if (ret < 0)
+ goto error;
ret = install_session_keyring(
- context, context->user->session_keyring);
+ cred->user->session_keyring);
+
if (ret < 0)
goto error;
+ goto reget_creds;
}
rcu_read_lock();
- key = rcu_dereference(context->signal->session_keyring);
+ key = rcu_dereference(cred->tgcred->session_keyring);
atomic_inc(&key->usage);
rcu_read_unlock();
+ key_ref = make_key_ref(key, 1);
break;
case KEY_SPEC_USER_KEYRING:
- key = context->user->uid_keyring;
+ if (!cred->user->uid_keyring) {
+ ret = install_user_keyrings();
+ if (ret < 0)
+ goto error;
+ }
+
+ key = cred->user->uid_keyring;
atomic_inc(&key->usage);
+ key_ref = make_key_ref(key, 1);
break;
case KEY_SPEC_USER_SESSION_KEYRING:
- key = context->user->session_keyring;
+ if (!cred->user->session_keyring) {
+ ret = install_user_keyrings();
+ if (ret < 0)
+ goto error;
+ }
+
+ key = cred->user->session_keyring;
atomic_inc(&key->usage);
+ key_ref = make_key_ref(key, 1);
break;
case KEY_SPEC_GROUP_KEYRING:
key = ERR_PTR(-EINVAL);
goto error;
+ case KEY_SPEC_REQKEY_AUTH_KEY:
+ key = cred->request_key_auth;
+ if (!key)
+ goto error;
+
+ atomic_inc(&key->usage);
+ key_ref = make_key_ref(key, 1);
+ break;
+
+ case KEY_SPEC_REQUESTOR_KEYRING:
+ if (!cred->request_key_auth)
+ goto error;
+
+ down_read(&cred->request_key_auth->sem);
+ if (cred->request_key_auth->flags & KEY_FLAG_REVOKED) {
+ key_ref = ERR_PTR(-EKEYREVOKED);
+ key = NULL;
+ } else {
+ rka = cred->request_key_auth->payload.data;
+ key = rka->dest_keyring;
+ atomic_inc(&key->usage);
+ }
+ up_read(&cred->request_key_auth->sem);
+ if (!key)
+ goto error;
+ key_ref = make_key_ref(key, 1);
+ break;
+
default:
- key = ERR_PTR(-EINVAL);
+ key_ref = ERR_PTR(-EINVAL);
if (id < 1)
goto error;
key = key_lookup(id);
- if (IS_ERR(key))
+ if (IS_ERR(key)) {
+ key_ref = ERR_CAST(key);
goto error;
+ }
+
+ key_ref = make_key_ref(key, 0);
+
+ /* check to see if we possess the key */
+ skey_ref = search_process_keyrings(key->type, key,
+ lookup_user_key_possessed,
+ cred);
+
+ if (!IS_ERR(skey_ref)) {
+ key_put(key);
+ key_ref = skey_ref;
+ }
+
break;
}
- /* check the status */
- if (perm) {
+ if (!partial) {
+ ret = wait_for_key_construction(key, true);
+ switch (ret) {
+ case -ERESTARTSYS:
+ goto invalid_key;
+ default:
+ if (perm)
+ goto invalid_key;
+ case 0:
+ break;
+ }
+ } else if (perm) {
ret = key_validate(key);
if (ret < 0)
goto invalid_key;
goto invalid_key;
/* check the permissions */
- ret = -EACCES;
-
- if (!key_task_permission(key, context, perm))
+ ret = key_task_permission(key_ref, cred, perm);
+ if (ret < 0)
goto invalid_key;
- error:
- return key;
+error:
+ put_cred(cred);
+ return key_ref;
- invalid_key:
- key_put(key);
- key = ERR_PTR(ret);
+invalid_key:
+ key_ref_put(key_ref);
+ key_ref = ERR_PTR(ret);
goto error;
+ /* if we attempted to install a keyring, then it may have caused new
+ * creds to be installed */
+reget_creds:
+ put_cred(cred);
+ goto try_again;
+
} /* end lookup_user_key() */
/*****************************************************************************/
*/
long join_session_keyring(const char *name)
{
- struct task_struct *tsk = current;
+ const struct cred *old;
+ struct cred *new;
struct key *keyring;
- long ret;
+ long ret, serial;
+
+ /* only permit this if there's a single thread in the thread group -
+ * this avoids us having to adjust the creds on all threads and risking
+ * ENOMEM */
+ if (!is_single_threaded(current))
+ return -EMLINK;
+
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
+ old = current_cred();
/* if no name is provided, install an anonymous keyring */
if (!name) {
- ret = install_session_keyring(tsk, NULL);
+ ret = install_session_keyring_to_cred(new, NULL);
if (ret < 0)
goto error;
- rcu_read_lock();
- ret = rcu_dereference(tsk->signal->session_keyring)->serial;
- rcu_read_unlock();
- goto error;
+ serial = new->tgcred->session_keyring->serial;
+ ret = commit_creds(new);
+ if (ret == 0)
+ ret = serial;
+ goto okay;
}
/* allow the user to join or create a named keyring */
- down(&key_session_sem);
+ mutex_lock(&key_session_mutex);
/* look for an existing keyring of this name */
- keyring = find_keyring_by_name(name, 0);
+ keyring = find_keyring_by_name(name, false);
if (PTR_ERR(keyring) == -ENOKEY) {
/* not found - try and create a new one */
- keyring = keyring_alloc(name, tsk->uid, tsk->gid, 0, NULL);
+ keyring = keyring_alloc(name, old->uid, old->gid, old,
+ KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
- goto error;
+ goto error2;
}
- }
- else if (IS_ERR(keyring)) {
+ } else if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error2;
}
/* we've got a keyring - now to install it */
- ret = install_session_keyring(tsk, keyring);
+ ret = install_session_keyring_to_cred(new, keyring);
if (ret < 0)
goto error2;
+ commit_creds(new);
+ mutex_unlock(&key_session_mutex);
+
ret = keyring->serial;
key_put(keyring);
-
- error2:
- up(&key_session_sem);
- error:
+okay:
return ret;
-} /* end join_session_keyring() */
+error2:
+ mutex_unlock(&key_session_mutex);
+error:
+ abort_creds(new);
+ return ret;
+}