mptcp: fix splat when closing unaccepted socket

If userspace exits before calling accept() on a listener that had at least
one new connection ready, we get:

   Attempt to release TCP socket in state 8

This happens because the mptcp socket gets cloned when the TCP connection
is ready, but the socket is never exposed to userspace.

The client additionally sends a DATA_FIN, which brings connection into
CLOSE_WAIT state.  This in turn prevents the orphan+state reset fixup
in mptcp_sock_destruct() from doing its job.

Fixes: 3721b9b64676b ("mptcp: Track received DATA_FIN sequence number and add related helpers")
Tested-by: Florian Westphal <>
Signed-off-by: Paolo Abeni <>
Signed-off-by: Mat Martineau <>
Signed-off-by: Jakub Kicinski <>
1 file changed