net/unix: sk_socket can disappear when state is unlocked
From: Mark Salyzyn <hidden>
Date: 2015-05-21 16:26:15
Also in:
lkml
Subsystem:
networking [general], networking [unix sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Linus Torvalds
got a rare NULL pointer dereference in clear_bit Signed-off-by: Mark Salyzyn <redacted> --- net/unix/af_unix.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 5266ea7..37a8925 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c@@ -1880,6 +1880,11 @@ static long unix_stream_data_wait(struct sock *sk, long timeo, unix_state_unlock(sk); timeo = freezable_schedule_timeout(timeo); unix_state_lock(sk); + + /* sk_socket may have been killed while unlocked */ + if (!sk->sk_socket) + break; + clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); }
--
2.2.0.rc0.207.ga3a616c