4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cong Wang <xiyou.wangcong@xxxxxxxxx> [ Upstream commit 0a3b8b2b215f9e84b82ae97df71292ccfd92b1e7 ] Before we unlock the sock in tipc_release(), we have to detach sk->sk_socket from sk, otherwise a parallel tipc_sk_fill_sock_diag() could stil read it after we free this socket. Fixes: c30b70deb5f4 ("tipc: implement socket diagnostics for AF_TIPC") Reported-and-tested-by: syzbot+48804b87c16588ad491d@xxxxxxxxxxxxxxxxxxxxxxxxx Cc: Jon Maloy <jon.maloy@xxxxxxxxxxxx> Cc: Ying Xue <ying.xue@xxxxxxxxxxxxx> Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx> Acked-by: Ying Xue <ying.xue@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/tipc/socket.c | 1 + 1 file changed, 1 insertion(+) --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -578,6 +578,7 @@ static int tipc_release(struct socket *s sk_stop_timer(sk, &sk->sk_timer); tipc_sk_remove(tsk); + sock_orphan(sk); /* Reject any messages that accumulated in backlog queue */ release_sock(sk); tipc_dest_list_purge(&tsk->cong_links);