*/
int install_user_keyrings(void)
{
- struct user_struct *user = current->cred->user;
+ struct user_struct *user;
+ const struct cred *cred;
struct key *uid_keyring, *session_keyring;
char buf[20];
int ret;
+ cred = current_cred();
+ user = cred->user;
+
kenter("%p{%u}", user, user->uid);
if (user->uid_keyring) {
uid_keyring = find_keyring_by_name(buf, true);
if (IS_ERR(uid_keyring)) {
uid_keyring = keyring_alloc(buf, user->uid, (gid_t) -1,
- current, KEY_ALLOC_IN_QUOTA,
+ cred, KEY_ALLOC_IN_QUOTA,
NULL);
if (IS_ERR(uid_keyring)) {
ret = PTR_ERR(uid_keyring);
if (IS_ERR(session_keyring)) {
session_keyring =
keyring_alloc(buf, user->uid, (gid_t) -1,
- current, KEY_ALLOC_IN_QUOTA,
- NULL);
+ cred, KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(session_keyring)) {
ret = PTR_ERR(session_keyring);
goto error_release;
return ret;
}
-/*****************************************************************************/
/*
- * 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(void)
+static int install_thread_keyring(void)
{
- struct task_struct *tsk = current;
- 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->cred->uid, tsk->cred->gid, tsk,
- KEY_ALLOC_QUOTA_OVERRUN, 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->cred->thread_keyring;
- tsk->cred->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(void)
+static int install_process_keyring(void)
{
- struct task_struct *tsk = current;
- struct key *keyring;
- char buf[20];
+ struct cred *new;
int ret;
- might_sleep();
-
- if (!tsk->cred->tgcred->process_keyring) {
- sprintf(buf, "_pid.%u", tsk->tgid);
-
- keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid, tsk,
- KEY_ALLOC_QUOTA_OVERRUN, NULL);
- if (IS_ERR(keyring)) {
- ret = PTR_ERR(keyring);
- goto error;
- }
-
- /* attach keyring */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- if (!tsk->cred->tgcred->process_keyring) {
- tsk->cred->tgcred->process_keyring = keyring;
- keyring = NULL;
- }
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
- 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 key *keyring)
+static int install_session_keyring_to_cred(struct cred *cred,
+ struct key *keyring)
{
- struct task_struct *tsk = current;
unsigned long flags;
struct key *old;
- char buf[20];
might_sleep();
/* create an empty session keyring */
if (!keyring) {
- sprintf(buf, "_ses.%u", tsk->tgid);
-
flags = KEY_ALLOC_QUOTA_OVERRUN;
- if (tsk->cred->tgcred->session_keyring)
+ if (cred->tgcred->session_keyring)
flags = KEY_ALLOC_IN_QUOTA;
- keyring = keyring_alloc(buf, tsk->cred->uid, tsk->cred->gid,
- tsk, flags, NULL);
+ keyring = keyring_alloc("_ses", cred->uid, cred->gid,
+ cred, flags, NULL);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
- }
- else {
+ } else {
atomic_inc(&keyring->usage);
}
/* install the keyring */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- old = tsk->cred->tgcred->session_keyring;
- rcu_assign_pointer(tsk->cred->tgcred->session_keyring, keyring);
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ 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 */
}
return 0;
+}
-} /* end install_session_keyring() */
-
-/*****************************************************************************/
/*
- * copy the keys for fork
+ * install a session keyring, discarding the old one
+ * - if a keyring is not supplied, an empty one is invented
*/
-int copy_keys(unsigned long clone_flags, struct task_struct *tsk)
+static int install_session_keyring(struct key *keyring)
{
- key_check(tsk->cred->thread_keyring);
- key_check(tsk->cred->request_key_auth);
-
- /* no thread keyring yet */
- tsk->cred->thread_keyring = NULL;
-
- /* copy the request_key() authorisation for this thread */
- key_get(tsk->cred->request_key_auth);
-
- return 0;
+ struct cred *new;
+ int ret;
-} /* end copy_keys() */
+ new = prepare_creds();
+ if (!new)
+ return -ENOMEM;
-/*****************************************************************************/
-/*
- * dispose of per-thread keys upon thread exit
- */
-void exit_keys(struct task_struct *tsk)
-{
- key_put(tsk->cred->thread_keyring);
- key_put(tsk->cred->request_key_auth);
+ ret = install_session_keyring_to_cred(new, NULL);
+ if (ret < 0) {
+ abort_creds(new);
+ return ret;
+ }
-} /* end exit_keys() */
+ return commit_creds(new);
+}
/*****************************************************************************/
/*
*/
int exec_keys(struct task_struct *tsk)
{
- struct key *old;
+ struct thread_group_cred *tgcred = NULL;
+ struct cred *new;
- /* newly exec'd tasks don't get a thread keyring */
- task_lock(tsk);
- old = tsk->cred->thread_keyring;
- tsk->cred->thread_keyring = NULL;
- task_unlock(tsk);
+#ifdef CONFIG_KEYS
+ tgcred = kmalloc(sizeof(*tgcred), GFP_KERNEL);
+ if (!tgcred)
+ return -ENOMEM;
+#endif
- key_put(old);
+ new = prepare_creds();
+ if (new < 0)
+ return -ENOMEM;
- /* discard the process keyring from a newly exec'd task */
- spin_lock_irq(&tsk->cred->tgcred->lock);
- old = tsk->cred->tgcred->process_keyring;
- tsk->cred->tgcred->process_keyring = NULL;
- spin_unlock_irq(&tsk->cred->tgcred->lock);
+ /* newly exec'd tasks don't get a thread keyring */
+ key_put(new->thread_keyring);
+ new->thread_keyring = NULL;
- key_put(old);
+ /* create a new per-thread-group creds for all this set of threads to
+ * share */
+ memcpy(tgcred, new->tgcred, sizeof(struct thread_group_cred));
- return 0;
+ atomic_set(&tgcred->usage, 1);
+ spin_lock_init(&tgcred->lock);
-} /* end exec_keys() */
+ /* inherit the session keyring; new process keyring */
+ key_get(tgcred->session_keyring);
+ tgcred->process_keyring = NULL;
-/*****************************************************************************/
-/*
- * deal with SUID programs
- * - we might want to make this invent a new session keyring
- */
-int suid_keys(struct task_struct *tsk)
-{
+ release_tgcred(new);
+ new->tgcred = tgcred;
+
+ commit_creds(new);
return 0;
-} /* end suid_keys() */
+} /* end exec_keys() */
/*****************************************************************************/
/*
key_ref_t search_process_keyrings(struct key_type *type,
const void *description,
key_match_func_t match,
- struct task_struct *context)
+ const struct cred *cred)
{
struct request_key_auth *rka;
- struct cred *cred;
key_ref_t key_ref, ret, err;
might_sleep();
- cred = get_task_cred(context);
-
/* 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;
* otherwise we want to return a sample error (probably -EACCES) if
if (cred->thread_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->thread_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
if (cred->tgcred->process_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->tgcred->process_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
make_key_ref(rcu_dereference(
cred->tgcred->session_keyring),
1),
- context, type, description, match);
+ cred, type, description, match);
rcu_read_unlock();
if (!IS_ERR(key_ref))
else if (cred->user->session_keyring) {
key_ref = keyring_search_aux(
make_key_ref(cred->user->session_keyring, 1),
- context, type, description, match);
+ cred, type, description, match);
if (!IS_ERR(key_ref))
goto found;
* - we don't permit access to request_key auth keys via this method
*/
if (cred->request_key_auth &&
- context == current &&
+ cred == current_cred() &&
type != &key_type_request_key_auth
) {
/* defend against the auth key being revoked */
rka = cred->request_key_auth->payload.data;
key_ref = search_process_keyrings(type, description,
- match, rka->context);
+ match, rka->cred);
up_read(&cred->request_key_auth->sem);
key_ref = ret ? ret : err;
found:
- put_cred(cred);
return key_ref;
} /* end search_process_keyrings() */
key_perm_t perm)
{
struct request_key_auth *rka;
- struct task_struct *t = current;
- struct cred *cred;
+ const struct cred *cred;
struct key *key;
key_ref_t key_ref, skey_ref;
int ret;
goto error;
ret = install_session_keyring(
cred->user->session_keyring);
+
if (ret < 0)
goto error;
goto reget_creds;
/* check to see if we possess the key */
skey_ref = search_process_keyrings(key->type, key,
lookup_user_key_possessed,
- current);
+ cred);
if (!IS_ERR(skey_ref)) {
key_put(key);
goto invalid_key;
/* check the permissions */
- ret = key_task_permission(key_ref, t, perm);
+ ret = key_task_permission(key_ref, cred, perm);
if (ret < 0)
goto invalid_key;
*/
long join_session_keyring(const char *name)
{
- struct task_struct *tsk = current;
- struct cred *cred = current->cred;
+ 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(NULL);
+ ret = install_session_keyring_to_cred(new, NULL);
if (ret < 0)
goto error;
- rcu_read_lock();
- ret = rcu_dereference(cred->tgcred->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 */
keyring = find_keyring_by_name(name, false);
if (PTR_ERR(keyring) == -ENOKEY) {
/* not found - try and create a new one */
- keyring = keyring_alloc(name, cred->uid, cred->gid, tsk,
+ keyring = keyring_alloc(name, old->uid, old->gid, old,
KEY_ALLOC_IN_QUOTA, NULL);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
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(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);
+okay:
+ return ret;
error2:
mutex_unlock(&key_session_mutex);
error:
+ abort_creds(new);
return ret;
-
-} /* end join_session_keyring() */
+}
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff