af_unix: dont send SCM_CREDENTIAL when dest socket is NULL

SCM_SCREDENTIALS should apply to write() syscalls only either source or destination socket asserted SOCK_PASSCRED. The original implememtation in maybe_add_creds is wrong, and breaks several LSB testcases ( i.e. /tset/LSB.os/netowkr/recvfrom/T.recvfrom). Origionally-authored-by: Karel Srot <[email protected]> Signed-off-by: Ding Tianhong <[email protected]> Acked-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
chewitt · Mar 26, 2013 · 14134f6 · 14134f6
1 parent 465c0a1
commit 14134f6
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
@@ -1412,8 +1412,8 @@ static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
 	if (UNIXCB(skb).cred)
 		return;
 	if (test_bit(SOCK_PASSCRED, &sock->flags) ||
-	    !other->sk_socket ||
-	    test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) {
+	    (other->sk_socket &&
+	    test_bit(SOCK_PASSCRED, &other->sk_socket->flags))) {
 		UNIXCB(skb).pid  = get_pid(task_tgid(current));
 		UNIXCB(skb).cred = get_current_cred();
 	}