unix/caif: sk_socket can disappear when state is unlocked

[ Upstream commit b48732e4a4 ]

got a rare NULL pointer dereference in clear_bit

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
----
v2: switch to sock_flag(sk, SOCK_DEAD) and added net/caif/caif_socket.c
v3: return -ECONNRESET in upstream caller of wait function for SOCK_DEAD
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mark Salyzyn 2015-05-26 08:22:19 -07:00 committed by Greg Kroah-Hartman
parent a7aef10597
commit 1f5105d64e
2 changed files with 16 additions and 0 deletions

View File

@ -332,6 +332,10 @@ 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);
}
@ -376,6 +380,10 @@ 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);

View File

@ -1893,6 +1893,10 @@ 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);
}
@ -1957,6 +1961,10 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
struct sk_buff *skb, *last;
unix_state_lock(sk);
if (sock_flag(sk, SOCK_DEAD)) {
err = -ECONNRESET;
goto unlock;
}
last = skb = skb_peek(&sk->sk_receive_queue);
again:
if (skb == NULL) {