return signal_pending(current) ? -ERESTARTSYS : 0;
}
-/*
- * call to complete the construction of a key
+/**
+ * complete_request_key - Complete the construction of a key.
+ * @cons: The key construction record.
+ * @error: The success or failute of the construction.
+ *
+ * Complete the attempt to construct a key. The key will be negated
+ * if an error is indicated. The authorisation key will be revoked
+ * unconditionally.
*/
void complete_request_key(struct key_construction *cons, int error)
{
EXPORT_SYMBOL(complete_request_key);
/*
- * request userspace finish the construction of a key
+ * Initialise a usermode helper that is going to have a specific session
+ * keyring.
+ *
+ * This is called in context of freshly forked kthread before kernel_execve(),
+ * so we can simply install the desired session_keyring at this point.
+ */
+static int umh_keys_init(struct subprocess_info *info)
+{
+ struct cred *cred = (struct cred*)current_cred();
+ struct key *keyring = info->data;
+
+ return install_session_keyring_to_cred(cred, keyring);
+}
+
+/*
+ * Clean up a usermode helper with session keyring.
+ */
+static void umh_keys_cleanup(struct subprocess_info *info)
+{
+ struct key *keyring = info->data;
+ key_put(keyring);
+}
+
+/*
+ * Call a usermode helper with a specific session keyring.
+ */
+static int call_usermodehelper_keys(char *path, char **argv, char **envp,
+ struct key *session_keyring, enum umh_wait wait)
+{
+ gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
+ struct subprocess_info *info =
+ call_usermodehelper_setup(path, argv, envp, gfp_mask);
+
+ if (!info)
+ return -ENOMEM;
+
+ call_usermodehelper_setfns(info, umh_keys_init, umh_keys_cleanup,
+ key_get(session_keyring));
+ return call_usermodehelper_exec(info, wait);
+}
+
+/*
+ * Request userspace finish the construction of a key
* - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
*/
static int call_sbin_request_key(struct key_construction *cons,
{
const struct cred *cred = current_cred();
key_serial_t prkey, sskey;
- struct key *key = cons->key, *authkey = cons->authkey, *keyring;
+ struct key *key = cons->key, *authkey = cons->authkey, *keyring,
+ *session;
char *argv[9], *envp[3], uid_str[12], gid_str[12];
char key_str[12], keyring_str[3][12];
char desc[20];
/* allocate a new session keyring */
sprintf(desc, "_req.%u", key->serial);
- keyring = keyring_alloc(desc, current_fsuid(), current_fsgid(), current,
+ cred = get_current_cred();
+ keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
KEY_ALLOC_QUOTA_OVERRUN, NULL);
+ put_cred(cred);
if (IS_ERR(keyring)) {
ret = PTR_ERR(keyring);
goto error_alloc;
}
/* attach the auth key to the session keyring */
- ret = __key_link(keyring, authkey);
+ ret = key_link(keyring, authkey);
if (ret < 0)
goto error_link;
/* we specify the process's default keyrings */
sprintf(keyring_str[0], "%d",
- cred->thread_keyring ?
- cred->thread_keyring->serial : 0);
+ cred->thread_keyring ? cred->thread_keyring->serial : 0);
prkey = 0;
if (cred->tgcred->process_keyring)
prkey = cred->tgcred->process_keyring->serial;
+ sprintf(keyring_str[1], "%d", prkey);
- if (cred->tgcred->session_keyring)
- sskey = rcu_dereference(cred->tgcred->session_keyring)->serial;
- else
- sskey = cred->user->session_keyring->serial;
+ rcu_read_lock();
+ session = rcu_dereference(cred->tgcred->session_keyring);
+ if (!session)
+ session = cred->user->session_keyring;
+ sskey = session->serial;
+ rcu_read_unlock();
sprintf(keyring_str[2], "%d", sskey);
key_put(keyring);
error_alloc:
- kleave(" = %d", ret);
complete_request_key(cons, ret);
+ kleave(" = %d", ret);
return ret;
}
/*
- * call out to userspace for key construction
- * - we ignore program failure and go on key status instead
+ * Call out to userspace for key construction.
+ *
+ * Program failure is ignored in favour of key status.
*/
static int construct_key(struct key *key, const void *callout_info,
size_t callout_len, void *aux,
}
/*
- * get the appropriate destination keyring for the request
- * - we return whatever keyring we select with an extra reference upon it which
- * the caller must release
+ * Get the appropriate destination keyring for the request.
+ *
+ * The keyring selected is returned with an extra reference upon it which the
+ * caller must release.
*/
static void construct_get_dest_keyring(struct key **_dest_keyring)
{
}
/*
- * allocate a new key in under-construction state and attempt to link it in to
- * the requested place
- * - may return a key that's already under construction instead
+ * Allocate a new key in under-construction state and attempt to link it in to
+ * the requested keyring.
+ *
+ * May return a key that's already under construction instead if there was a
+ * race between two thread calling request_key().
*/
static int construct_alloc_key(struct key_type *type,
const char *description,
struct key_user *user,
struct key **_key)
{
+ const struct cred *cred = current_cred();
+ unsigned long prealloc;
struct key *key;
key_ref_t key_ref;
+ int ret;
kenter("%s,%s,,,", type->name, description);
+ *_key = NULL;
mutex_lock(&user->cons_lock);
- key = key_alloc(type, description,
- current_fsuid(), current_fsgid(), current, KEY_POS_ALL,
- flags);
+ key = key_alloc(type, description, cred->fsuid, cred->fsgid, cred,
+ KEY_POS_ALL, flags);
if (IS_ERR(key))
goto alloc_failed;
set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
- down_write(&dest_keyring->sem);
+ if (dest_keyring) {
+ ret = __key_link_begin(dest_keyring, type, description,
+ &prealloc);
+ if (ret < 0)
+ goto link_prealloc_failed;
+ }
/* attach the key to the destination keyring under lock, but we do need
* to do another check just in case someone beat us to it whilst we
* waited for locks */
mutex_lock(&key_construction_mutex);
- key_ref = search_process_keyrings(type, description, type->match,
- current);
+ key_ref = search_process_keyrings(type, description, type->match, cred);
if (!IS_ERR(key_ref))
goto key_already_present;
- __key_link(dest_keyring, key);
+ if (dest_keyring)
+ __key_link(dest_keyring, key, &prealloc);
mutex_unlock(&key_construction_mutex);
- up_write(&dest_keyring->sem);
+ if (dest_keyring)
+ __key_link_end(dest_keyring, type, prealloc);
mutex_unlock(&user->cons_lock);
*_key = key;
kleave(" = 0 [%d]", key_serial(key));
return 0;
+ /* the key is now present - we tell the caller that we found it by
+ * returning -EINPROGRESS */
key_already_present:
+ key_put(key);
mutex_unlock(&key_construction_mutex);
- if (dest_keyring)
- up_write(&dest_keyring->sem);
+ key = key_ref_to_ptr(key_ref);
+ if (dest_keyring) {
+ ret = __key_link_check_live_key(dest_keyring, key);
+ if (ret == 0)
+ __key_link(dest_keyring, key, &prealloc);
+ __key_link_end(dest_keyring, type, prealloc);
+ if (ret < 0)
+ goto link_check_failed;
+ }
mutex_unlock(&user->cons_lock);
- key_put(key);
- *_key = key = key_ref_to_ptr(key_ref);
+ *_key = key;
kleave(" = -EINPROGRESS [%d]", key_serial(key));
return -EINPROGRESS;
+link_check_failed:
+ mutex_unlock(&user->cons_lock);
+ key_put(key);
+ kleave(" = %d [linkcheck]", ret);
+ return ret;
+
+link_prealloc_failed:
+ mutex_unlock(&user->cons_lock);
+ kleave(" = %d [prelink]", ret);
+ return ret;
+
alloc_failed:
mutex_unlock(&user->cons_lock);
- *_key = NULL;
kleave(" = %ld", PTR_ERR(key));
return PTR_ERR(key);
}
/*
- * commence key construction
+ * Commence key construction.
*/
static struct key *construct_key_and_link(struct key_type *type,
const char *description,
struct key *key;
int ret;
- user = key_user_lookup(current_fsuid());
+ kenter("");
+
+ user = key_user_lookup(current_fsuid(), current_user_ns());
if (!user)
return ERR_PTR(-ENOMEM);
if (ret == 0) {
ret = construct_key(key, callout_info, callout_len, aux,
dest_keyring);
- if (ret < 0)
+ if (ret < 0) {
+ kdebug("cons failed");
goto construction_failed;
+ }
+ } else if (ret == -EINPROGRESS) {
+ ret = 0;
+ } else {
+ key = ERR_PTR(ret);
}
key_put(dest_keyring);
+ kleave(" = key %d", key_serial(key));
return key;
construction_failed:
key_negate_and_link(key, key_negative_timeout, NULL, NULL);
key_put(key);
key_put(dest_keyring);
+ kleave(" = %d", ret);
return ERR_PTR(ret);
}
-/*
- * request a key
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - cache the key in an appropriate keyring
+/**
+ * request_key_and_link - Request a key and cache it in a keyring.
+ * @type: The type of key we want.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ * @dest_keyring: Where to cache the key.
+ * @flags: Flags to key_alloc().
+ *
+ * A key matching the specified criteria is searched for in the process's
+ * keyrings and returned with its usage count incremented if found. Otherwise,
+ * if callout_info is not NULL, a key will be allocated and some service
+ * (probably in userspace) will be asked to instantiate it.
+ *
+ * If successfully found or created, the key will be linked to the destination
+ * keyring if one is provided.
+ *
+ * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED
+ * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was
+ * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT
+ * if insufficient key quota was available to create a new key; or -ENOMEM if
+ * insufficient memory was available.
+ *
+ * If the returned key was created, then it may still be under construction,
+ * and wait_for_key_construction() should be used to wait for that to complete.
*/
struct key *request_key_and_link(struct key_type *type,
const char *description,
struct key *dest_keyring,
unsigned long flags)
{
+ const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
+ int ret;
kenter("%s,%s,%p,%zu,%p,%p,%lx",
type->name, description, callout_info, callout_len, aux,
/* search all the process keyrings for a key */
key_ref = search_process_keyrings(type, description, type->match,
- current);
+ cred);
if (!IS_ERR(key_ref)) {
key = key_ref_to_ptr(key_ref);
+ if (dest_keyring) {
+ construct_get_dest_keyring(&dest_keyring);
+ ret = key_link(dest_keyring, key);
+ key_put(dest_keyring);
+ if (ret < 0) {
+ key_put(key);
+ key = ERR_PTR(ret);
+ goto error;
+ }
+ }
} else if (PTR_ERR(key_ref) != -EAGAIN) {
key = ERR_CAST(key_ref);
} else {
return key;
}
-/*
- * wait for construction of a key to complete
+/**
+ * wait_for_key_construction - Wait for construction of a key to complete
+ * @key: The key being waited for.
+ * @intr: Whether to wait interruptibly.
+ *
+ * Wait for a key to finish being constructed.
+ *
+ * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY
+ * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was
+ * revoked or expired.
*/
int wait_for_key_construction(struct key *key, bool intr)
{
intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
if (ret < 0)
return ret;
+ if (test_bit(KEY_FLAG_NEGATIVE, &key->flags))
+ return -ENOKEY;
return key_validate(key);
}
EXPORT_SYMBOL(wait_for_key_construction);
-/*
- * request a key
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - waits uninterruptible for creation to complete
+/**
+ * request_key - Request a key and wait for construction
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found, new keys are always allocated in the user's quota,
+ * the callout_info must be a NUL-terminated string and no auxiliary data can
+ * be passed.
+ *
+ * Furthermore, it then works as wait_for_key_construction() to wait for the
+ * completion of keys undergoing construction with a non-interruptible wait.
*/
struct key *request_key(struct key_type *type,
const char *description,
}
EXPORT_SYMBOL(request_key);
-/*
- * request a key with auxiliary data for the upcaller
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
- * - waits uninterruptible for creation to complete
+/**
+ * request_key_with_auxdata - Request a key with auxiliary data for the upcaller
+ * @type: The type of key we want.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found and new keys are always allocated in the user's quota.
+ *
+ * Furthermore, it then works as wait_for_key_construction() to wait for the
+ * completion of keys undergoing construction with a non-interruptible wait.
*/
struct key *request_key_with_auxdata(struct key_type *type,
const char *description,
EXPORT_SYMBOL(request_key_with_auxdata);
/*
- * request a key (allow async construction)
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
+ * request_key_async - Request a key (allow async construction)
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found, new keys are always allocated in the user's quota and
+ * no auxiliary data can be passed.
+ *
+ * The caller should call wait_for_key_construction() to wait for the
+ * completion of the returned key if it is still undergoing construction.
*/
struct key *request_key_async(struct key_type *type,
const char *description,
/*
* request a key with auxiliary data for the upcaller (allow async construction)
- * - search the process's keyrings
- * - check the list of keys being created or updated
- * - call out to userspace for a key if supplementary info was provided
+ * @type: Type of key.
+ * @description: The searchable description of the key.
+ * @callout_info: The data to pass to the instantiation upcall (or NULL).
+ * @callout_len: The length of callout_info.
+ * @aux: Auxiliary data for the upcall.
+ *
+ * As for request_key_and_link() except that it does not add the returned key
+ * to a keyring if found and new keys are always allocated in the user's quota.
+ *
+ * The caller should call wait_for_key_construction() to wait for the
+ * completion of the returned key if it is still undergoing construction.
*/
struct key *request_key_async_with_auxdata(struct key_type *type,
const char *description,
projects / linux-flexiantxendom0-natty.git / blobdiff