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-rw-r--r--security/keys/request_key.c135
1 files changed, 82 insertions, 53 deletions
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index abea08f87fe..0e04f72ef2d 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -19,6 +19,8 @@
#include <linux/slab.h>
#include "internal.h"
+#define key_negative_timeout 60 /* default timeout on a negative key's existence */
+
/*
* wait_on_bit() sleep function for uninterruptible waiting
*/
@@ -64,7 +66,7 @@ static int call_sbin_request_key(struct key_construction *cons,
const char *op,
void *aux)
{
- struct task_struct *tsk = current;
+ const struct cred *cred = current_cred();
key_serial_t prkey, sskey;
struct key *key = cons->key, *authkey = cons->authkey, *keyring;
char *argv[9], *envp[3], uid_str[12], gid_str[12];
@@ -74,15 +76,17 @@ static int call_sbin_request_key(struct key_construction *cons,
kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
- ret = install_user_keyrings(tsk);
+ ret = install_user_keyrings();
if (ret < 0)
goto error_alloc;
/* 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;
@@ -94,29 +98,24 @@ static int call_sbin_request_key(struct key_construction *cons,
goto error_link;
/* record the UID and GID */
- sprintf(uid_str, "%d", current->fsuid);
- sprintf(gid_str, "%d", current->fsgid);
+ sprintf(uid_str, "%d", cred->fsuid);
+ sprintf(gid_str, "%d", cred->fsgid);
/* we say which key is under construction */
sprintf(key_str, "%d", key->serial);
/* we specify the process's default keyrings */
sprintf(keyring_str[0], "%d",
- tsk->thread_keyring ? tsk->thread_keyring->serial : 0);
+ cred->thread_keyring ? cred->thread_keyring->serial : 0);
prkey = 0;
- if (tsk->signal->process_keyring)
- prkey = tsk->signal->process_keyring->serial;
-
- sprintf(keyring_str[1], "%d", prkey);
+ if (cred->tgcred->process_keyring)
+ prkey = cred->tgcred->process_keyring->serial;
- if (tsk->signal->session_keyring) {
- rcu_read_lock();
- sskey = rcu_dereference(tsk->signal->session_keyring)->serial;
- rcu_read_unlock();
- } else {
- sskey = tsk->user->session_keyring->serial;
- }
+ if (cred->tgcred->session_keyring)
+ sskey = rcu_dereference(cred->tgcred->session_keyring)->serial;
+ else
+ sskey = cred->user->session_keyring->serial;
sprintf(keyring_str[2], "%d", sskey);
@@ -157,8 +156,8 @@ error_link:
key_put(keyring);
error_alloc:
- kleave(" = %d", ret);
complete_request_key(cons, ret);
+ kleave(" = %d", ret);
return ret;
}
@@ -167,7 +166,8 @@ 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;
@@ -181,7 +181,8 @@ 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);
@@ -209,46 +210,67 @@ 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 task_struct *tsk = current;
- struct key *drop = NULL;
+ struct request_key_auth *rka;
+ const struct cred *cred = current_cred();
+ 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) {
- switch (tsk->jit_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 (cred->jit_keyring) {
case KEY_REQKEY_DEFL_DEFAULT:
+ case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
+ if (cred->request_key_auth) {
+ authkey = cred->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(cred->thread_keyring);
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
- dest_keyring = tsk->signal->process_keyring;
+ dest_keyring = key_get(cred->tgcred->process_keyring);
if (dest_keyring)
break;
case KEY_REQKEY_DEFL_SESSION_KEYRING:
rcu_read_lock();
dest_keyring = key_get(
- rcu_dereference(tsk->signal->session_keyring));
+ rcu_dereference(cred->tgcred->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(cred->user->session_keyring);
break;
case KEY_REQKEY_DEFL_USER_KEYRING:
- dest_keyring = tsk->user->uid_keyring;
+ dest_keyring = key_get(cred->user->uid_keyring);
break;
case KEY_REQKEY_DEFL_GROUP_KEYRING:
@@ -257,10 +279,9 @@ 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;
}
/*
@@ -275,6 +296,7 @@ static int construct_alloc_key(struct key_type *type,
struct key_user *user,
struct key **_key)
{
+ const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
@@ -282,33 +304,28 @@ static int construct_alloc_key(struct key_type *type,
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);
- 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
* 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;
- 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));
@@ -346,25 +363,36 @@ static struct key *construct_key_and_link(struct key_type *type,
struct key *key;
int ret;
- user = key_user_lookup(current->fsuid);
+ kenter("");
+
+ user = key_user_lookup(current_fsuid());
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);
- if (ret < 0)
+ ret = construct_key(key, callout_info, callout_len, aux,
+ dest_keyring);
+ if (ret < 0) {
+ kdebug("cons failed");
goto construction_failed;
+ }
}
+ 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);
}
@@ -383,6 +411,7 @@ struct key *request_key_and_link(struct key_type *type,
struct key *dest_keyring,
unsigned long flags)
{
+ const struct cred *cred = current_cred();
struct key *key;
key_ref_t key_ref;
@@ -392,7 +421,7 @@ struct key *request_key_and_link(struct key_type *type,
/* 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);