From 7449299aa1e791d60abc5556f2ecf7f1ba039be9 Mon Sep 17 00:00:00 2001 From: Mark Salyzyn Date: Thu, 21 May 2015 09:25:02 -0700 Subject: [PATCH] net/unix: sk_socket can disappear when state is unlocked got a rare NULL pointer dereference in clear_bit Signed-off-by: Mark Salyzyn Bug: 21252747 Change-Id: I27e70f2543034097c8a590a212c2c6fa846fe695 --- net/caif/caif_socket.c | 8 ++++++++ net/unix/af_unix.c | 8 ++++++++ 2 files changed, 16 insertions(+) diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c index 05a41c7ec304..955e83af1f3a 100644 --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -334,6 +334,10 @@ static long caif_stream_data_wait(struct sock *sk, long timeo) release_sock(sk); timeo = schedule_timeout(timeo); lock_sock(sk); + + if (sock_flag(sk, SOCK_DEAD)) + break; + clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); } @@ -380,6 +384,10 @@ static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock, struct sk_buff *skb; lock_sock(sk); + if (sock_flag(sk, SOCK_DEAD)) { + err = -ECONNRESET; + goto unlock; + } skb = skb_dequeue(&sk->sk_receive_queue); caif_check_flow_release(sk); diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index c4ce243824bb..53e062a2eee0 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1882,6 +1882,10 @@ static long unix_stream_data_wait(struct sock *sk, long timeo, unix_state_unlock(sk); timeo = freezable_schedule_timeout(timeo); unix_state_lock(sk); + + if (sock_flag(sk, SOCK_DEAD)) + break; + clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); } @@ -1939,6 +1943,10 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, struct sk_buff *skb, *last; unix_state_lock(sk); + if (sock_flag(sg, SOCK_DEAD)) { + err = -ECONNRESET; + goto unlock; + } last = skb = skb_peek(&sk->sk_receive_queue); again: if (skb == NULL) { -- 2.34.1