KEYS: fix key refcount leak in keyctl_read_key()

commit 7fc0786d956d9e59b68d282be9b156179846ea3d upstream.

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.

Fixes: 29db91906340 ("[PATCH] Keys: Add LSM hooks for key management [try #3]")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index ed50ef1..659d1cb 100644 (file)
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -684,7 +684,7 @@ 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