unix/caif: sk_socket can disappear when state is unlocked

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>
This commit is contained in:
Mark Salyzyn 2015-05-26 08:22:19 -07:00 committed by David S. Miller
parent 983942a5ea
commit b48732e4a4
2 changed files with 16 additions and 0 deletions

View File

@ -330,6 +330,10 @@ 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);
}
@ -373,6 +377,10 @@ static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg,
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

@ -1880,6 +1880,10 @@ 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 socket *sock, struct msghdr *msg,
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) {