Reenabled linux-xen and xen-image build

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.25 / patches.arch / s390-08-05-af_iucv-msgpeek-fix.patch

From: Gerald Schaefer <geraldsc@de.ibm.com>
Subject: af_iucv: System hang if recvmsg() is used with MSG_PEEK
References: bnc#466462,LTC#51136

Symptom:     Receiving socket data with MSG_PEEK flag set causes systen hang
Problem:     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 also freed twice and causes a kernel oops.
Solution:    Remove the skb_queue_head() call for MSG_PEEK, because the
             skb_recv_datagram() function already handles MSG_PEEK (it
             actually does not dequeue the skb).

Acked-by: John Jolly <jjolly@suse.de>
---
 net/iucv/af_iucv.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -789,6 +789,8 @@ static int iucv_sock_recvmsg(struct kioc
 
 	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)
@@ -836,9 +838,7 @@ static int iucv_sock_recvmsg(struct kioc
 				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;