KEYS: fix key refcount leak in keyctl_read_key()

From: Eric Biggers <[email protected]>

In keyctl_read_key(), if key_permission() were to return an error code other than EACCES, we would leak a the reference to the key. This can't actually happen currently because key_permission() can only return an error code other than EACCES if security_key_permission() does, only SELinux and Smack implement that hook, and neither can return an error code other than EACCES. But it should still be fixed, as it is a bug waiting to happen.

---
 security/keys/keyctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 552e4460683b..365ff85d7e27 100644
@@ -776,7 +776,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
 	if (ret = 0)
 		goto can_read_key;
 	if (ret != -EACCES)
-		goto error;
+		goto error2;
 
 	/* we can't; see if it's searchable from this process's keyrings
 	 * - we automatically take account of the fact that it may be

2.14.1.690.gbb1197296e-goog