From: Paolo Abeni pabeni@redhat.com
[ Upstream commit 578c18eff1627d6a911f08f4cf351eca41fdcc7d ]
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") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/185 Tested-by: Florian Westphal fw@strlen.de Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Link: https://lore.kernel.org/r/20210507001638.225468-1-mathew.j.martineau@linux.i... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/mptcp/subflow.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index d17d39ccdf34..4fe7acaa472f 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -524,8 +524,7 @@ static void mptcp_sock_destruct(struct sock *sk) * ESTABLISHED state and will not have the SOCK_DEAD flag. * Both result in warnings from inet_sock_destruct. */ - - if (sk->sk_state == TCP_ESTABLISHED) { + if ((1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) { sk->sk_state = TCP_CLOSE; WARN_ON_ONCE(sk->sk_socket); sock_orphan(sk);