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-rw-r--r--security/keys/request_key.c75
1 files changed, 51 insertions, 24 deletions
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 91953c81449..8e9d93b4a40 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -76,6 +76,10 @@ static int call_sbin_request_key(struct key_construction *cons,
kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
+ ret = install_user_keyrings();
+ if (ret < 0)
+ goto error_alloc;
+
/* allocate a new session keyring */
sprintf(desc, "_req.%u", key->serial);
@@ -165,7 +169,8 @@ error_alloc:
* - we ignore program failure and go on key status instead
*/
static int construct_key(struct key *key, const void *callout_info,
- size_t callout_len, void *aux)
+ size_t callout_len, void *aux,
+ struct key *dest_keyring)
{
struct key_construction *cons;
request_key_actor_t actor;
@@ -179,7 +184,8 @@ static int construct_key(struct key *key, const void *callout_info,
return -ENOMEM;
/* allocate an authorisation key */
- authkey = request_key_auth_new(key, callout_info, callout_len);
+ authkey = request_key_auth_new(key, callout_info, callout_len,
+ dest_keyring);
if (IS_ERR(authkey)) {
kfree(cons);
ret = PTR_ERR(authkey);
@@ -207,27 +213,48 @@ static int construct_key(struct key *key, const void *callout_info,
}
/*
- * link a key to the appropriate destination keyring
- * - the caller must hold a write lock on the destination keyring
+ * 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
*/
-static void construct_key_make_link(struct key *key, struct key *dest_keyring)
+static void construct_get_dest_keyring(struct key **_dest_keyring)
{
+ struct request_key_auth *rka;
struct task_struct *tsk = current;
- struct key *drop = NULL;
+ struct key *dest_keyring = *_dest_keyring, *authkey;
- kenter("{%d},%p", key->serial, dest_keyring);
+ kenter("%p", dest_keyring);
/* find the appropriate keyring */
- if (!dest_keyring) {
+ if (dest_keyring) {
+ /* the caller supplied one */
+ key_get(dest_keyring);
+ } else {
+ /* use a default keyring; falling through the cases until we
+ * find one that we actually have */
switch (tsk->jit_keyring) {
case KEY_REQKEY_DEFL_DEFAULT:
+ case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
+ if (tsk->request_key_auth) {
+ authkey = tsk->request_key_auth;
+ down_read(&authkey->sem);
+ rka = authkey->payload.data;
+ if (!test_bit(KEY_FLAG_REVOKED,
+ &authkey->flags))
+ dest_keyring =
+ key_get(rka->dest_keyring);
+ up_read(&authkey->sem);
+ if (dest_keyring)
+ break;
+ }
+
case KEY_REQKEY_DEFL_THREAD_KEYRING:
- dest_keyring = tsk->thread_keyring;
+ dest_keyring = key_get(tsk->thread_keyring);
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
- dest_keyring = tsk->signal->process_keyring;
+ dest_keyring = key_get(tsk->signal->process_keyring);
if (dest_keyring)
break;
@@ -236,17 +263,16 @@ static void construct_key_make_link(struct key *key, struct key *dest_keyring)
dest_keyring = key_get(
rcu_dereference(tsk->signal->session_keyring));
rcu_read_unlock();
- drop = dest_keyring;
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
- dest_keyring = tsk->user->session_keyring;
+ dest_keyring = key_get(tsk->user->session_keyring);
break;
case KEY_REQKEY_DEFL_USER_KEYRING:
- dest_keyring = tsk->user->uid_keyring;
+ dest_keyring = key_get(tsk->user->uid_keyring);
break;
case KEY_REQKEY_DEFL_GROUP_KEYRING:
@@ -255,10 +281,9 @@ static void construct_key_make_link(struct key *key, struct key *dest_keyring)
}
}
- /* and attach the key to it */
- __key_link(dest_keyring, key);
- key_put(drop);
- kleave("");
+ *_dest_keyring = dest_keyring;
+ kleave(" [dk %d]", key_serial(dest_keyring));
+ return;
}
/*
@@ -288,8 +313,7 @@ static int construct_alloc_key(struct key_type *type,
set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
- if (dest_keyring)
- down_write(&dest_keyring->sem);
+ down_write(&dest_keyring->sem);
/* 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
@@ -301,12 +325,10 @@ static int construct_alloc_key(struct key_type *type,
if (!IS_ERR(key_ref))
goto key_already_present;
- if (dest_keyring)
- construct_key_make_link(key, dest_keyring);
+ __key_link(dest_keyring, key);
mutex_unlock(&key_construction_mutex);
- if (dest_keyring)
- up_write(&dest_keyring->sem);
+ up_write(&dest_keyring->sem);
mutex_unlock(&user->cons_lock);
*_key = key;
kleave(" = 0 [%d]", key_serial(key));
@@ -348,21 +370,26 @@ static struct key *construct_key_and_link(struct key_type *type,
if (!user)
return ERR_PTR(-ENOMEM);
+ construct_get_dest_keyring(&dest_keyring);
+
ret = construct_alloc_key(type, description, dest_keyring, flags, user,
&key);
key_user_put(user);
if (ret == 0) {
- ret = construct_key(key, callout_info, callout_len, aux);
+ ret = construct_key(key, callout_info, callout_len, aux,
+ dest_keyring);
if (ret < 0)
goto construction_failed;
}
+ key_put(dest_keyring);
return key;
construction_failed:
key_negate_and_link(key, key_negative_timeout, NULL, NULL);
key_put(key);
+ key_put(dest_keyring);
return ERR_PTR(ret);
}