af_iucv: fix oops in iucv_sock_recvmsg() for MSG_PEEK flag

If iucv_sock_recvmsg() is called with MSG_PEEK flag set, the skb is enqueued
twice. If the socket is then closed, the pointer to the skb is freed twice.

Remove the skb_queue_head() call for MSG_PEEK, because the skb_recv_datagram()
function already handles MSG_PEEK (does not dequeue the skb).

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hendrik Brueckner 2009-04-21 06:04:21 +00:00 committed by David S. Miller
parent bbe188c8f1
commit 60d3705fcb
1 changed files with 3 additions and 3 deletions

View File

@ -814,6 +814,8 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
/* receive/dequeue next skb:
* the function understands MSG_PEEK and, thus, does not dequeue skb */
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb) {
if (sk->sk_shutdown & RCV_SHUTDOWN)
@ -861,9 +863,7 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
iucv_process_message_q(sk);
spin_unlock_bh(&iucv->message_q.lock);
}
} else
skb_queue_head(&sk->sk_receive_queue, skb);
}
done:
return err ? : copied;