From: John Ericson Date: Sat, 18 Jul 2026 18:29:01 +0000 (-0400) Subject: af_unix: fix listen() succeeding on sockets in the wrong state X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f0d9c3ffc2b5fc2ffacb56b3036155ce7a940a12;p=thirdparty%2Fkernel%2Fstable.git af_unix: fix listen() succeeding on sockets in the wrong state Commit fd0a109a0f6b ("net, pidfs: prepare for handing out pidfds for reaped sk->sk_peer_pid") inserted a prepare_peercred() call between err = -EINVAL and the socket-state check in unix_listen(). Since prepare_peercred() leaves err at 0 on success, listen() on an AF_UNIX socket that is not in TCP_CLOSE or TCP_LISTEN state (e.g. one that is already connected) now silently returns success without doing anything, instead of failing with EINVAL as it did before. Fixes: fd0a109a0f6b ("net, pidfs: prepare for handing out pidfds for reaped sk->sk_peer_pid") Signed-off-by: John Ericson Link: https://patch.msgid.link/20260718182903.2295560-1-John.Ericson@Obsidian.Systems Signed-off-by: Jakub Kicinski --- diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index f7a9d55eee8a1..10ed9421e43aa 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -823,6 +823,7 @@ static int unix_listen(struct socket *sock, int backlog) if (err) goto out; unix_state_lock(sk); + err = -EINVAL; if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN) goto out_unlock; if (backlog > sk->sk_max_ack_backlog)