From aed20a53a7d91e45c6a8cb8920c77aaaa88f76ee Mon Sep 17 00:00:00 2001 From: Sowmini Varadhan Date: Sun, 16 Jul 2017 16:43:46 -0700 Subject: rds: cancel send/recv work before queuing connection shutdown We could end up executing rds_conn_shutdown before the rds_recv_worker thread, then rds_conn_shutdown -> rds_tcp_conn_shutdown can do a sock_release and set sock->sk to null, which may interleave in bad ways with rds_recv_worker, e.g., it could result in: "BUG: unable to handle kernel NULL pointer dereference at 0000000000000078" [ffff881769f6fd70] release_sock at ffffffff815f337b [ffff881769f6fd90] rds_tcp_recv at ffffffffa043c888 [rds_tcp] [ffff881769f6fdb0] rds_recv_worker at ffffffffa04a4810 [rds] [ffff881769f6fde0] process_one_work at ffffffff810a14c1 [ffff881769f6fe40] worker_thread at ffffffff810a1940 [ffff881769f6fec0] kthread at ffffffff810a6b1e Also, do not enqueue any new shutdown workq items when the connection is shutting down (this may happen for rds-tcp in softirq mode, if a FIN or CLOSE is received while the modules is in the middle of an unload) Signed-off-by: Sowmini Varadhan Signed-off-by: David S. Miller --- net/rds/tcp_connect.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/rds/tcp_connect.c') diff --git a/net/rds/tcp_connect.c b/net/rds/tcp_connect.c index cbe08a1fa4c7..46f74dad0e16 100644 --- a/net/rds/tcp_connect.c +++ b/net/rds/tcp_connect.c @@ -69,14 +69,14 @@ void rds_tcp_state_change(struct sock *sk) if (!IS_CANONICAL(cp->cp_conn->c_laddr, cp->cp_conn->c_faddr) && rds_conn_path_transition(cp, RDS_CONN_CONNECTING, RDS_CONN_ERROR)) { - rds_conn_path_drop(cp); + rds_conn_path_drop(cp, false); } else { rds_connect_path_complete(cp, RDS_CONN_CONNECTING); } break; case TCP_CLOSE_WAIT: case TCP_CLOSE: - rds_conn_path_drop(cp); + rds_conn_path_drop(cp, false); default: break; } -- cgit