CRED: Wrap task credential accesses in the key management code

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/keys/key.c

@@ -802,7 +802,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 	}
 
 	/* allocate a new key */
-	key = key_alloc(ktype, description, current->fsuid, current->fsgid,
+	key = key_alloc(ktype, description, current_fsuid(), current_fsgid(),
 			current, perm, flags);
 	if (IS_ERR(key)) {
 		key_ref = ERR_CAST(key);

security/keys/keyctl.c

@@ -817,7 +817,7 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
 	down_write(&key->sem);
 
 	/* if we're not the sysadmin, we can only change a key that we own */
-	if (capable(CAP_SYS_ADMIN) || key->uid == current->fsuid) {
+	if (capable(CAP_SYS_ADMIN) || key->uid == current_fsuid()) {
 		key->perm = perm;
 		ret = 0;
 	}

security/keys/request_key.c

@@ -77,7 +77,7 @@ static int call_sbin_request_key(struct key_construction *cons,
 	/* allocate a new session keyring */
 	sprintf(desc, "_req.%u", key->serial);
 
-	keyring = keyring_alloc(desc, current->fsuid, current->fsgid, current,
+	keyring = keyring_alloc(desc, current_fsuid(), current_fsgid(), current,
 				KEY_ALLOC_QUOTA_OVERRUN, NULL);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
@@ -90,8 +90,8 @@ 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", current_fsuid());
+	sprintf(gid_str, "%d", current_fsgid());
 
 	/* we say which key is under construction */
 	sprintf(key_str, "%d", key->serial);
@@ -279,7 +279,7 @@ 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,
+			current_fsuid(), current_fsgid(), current, KEY_POS_ALL,
 			flags);
 	if (IS_ERR(key))
 		goto alloc_failed;
@@ -342,7 +342,7 @@ static struct key *construct_key_and_link(struct key_type *type,
 	struct key *key;
 	int ret;
 
-	user = key_user_lookup(current->fsuid);
+	user = key_user_lookup(current_fsuid());
 	if (!user)
 		return ERR_PTR(-ENOMEM);
 

security/keys/request_key_auth.c

@@ -195,7 +195,7 @@ struct key *request_key_auth_new(struct key *target, const void *callout_info,
 	sprintf(desc, "%x", target->serial);
 
 	authkey = key_alloc(&key_type_request_key_auth, desc,
-			    current->fsuid, current->fsgid, current,
+			    current_fsuid(), current_fsgid(), current,
 			    KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
 			    KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA);
 	if (IS_ERR(authkey)) {