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Commit 60d3705f authored by Hendrik Brueckner's avatar Hendrik Brueckner Committed by David S. Miller
Browse files

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: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: default avatarUrsula Braun <ursula.braun@de.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bbe188c8

net/iucv/af_iucv.c

+3 −3
Original line number Original line Diff line number Diff line
@@ -814,6 +814,8 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock, 




	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);

	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);

	skb = skb_recv_datagram(sk, flags, noblock, &err);

	if (!skb) {

	if (!skb) {

		if (sk->sk_shutdown & RCV_SHUTDOWN)

		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);

				iucv_process_message_q(sk);

			spin_unlock_bh(&iucv->message_q.lock);

			spin_unlock_bh(&iucv->message_q.lock);

		}

		}



	}

	} else

		skb_queue_head(&sk->sk_receive_queue, skb);





done:

done:

	return err ? : copied;

	return err ? : copied;