From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762274AbbA2Chj (ORCPT ); Wed, 28 Jan 2015 21:37:39 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:47000 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965254AbbA2Chb (ORCPT ); Wed, 28 Jan 2015 21:37:31 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: David Vrabel , "David S. Miller" , Stefan Bader , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 018/139] xen-netfront: use correct linear area after linearizing an skb Date: Wed, 28 Jan 2015 14:19:21 -0800 Message-Id: <1422483682-15393-19-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1422483682-15393-1-git-send-email-kamal@canonical.com> References: <1422483682-15393-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11-ckt15 -stable review patch. If anyone has any objections, please let me know. ------------------ From: David Vrabel commit 11d3d2a16cc1f05c6ece69a4392e99efb85666a6 upstream. Commit 97a6d1bb2b658ac85ed88205ccd1ab809899884d (xen-netfront: Fix handling packets on compound pages with skb_linearize) attempted to fix a problem where an skb that would have required too many slots would be dropped causing TCP connections to stall. However, it filled in the first slot using the original buffer and not the new one and would use the wrong offset and grant access to the wrong page. Netback would notice the malformed request and stop all traffic on the VIF, reporting: vif vif-3-0 vif3.0: txreq.offset: 85e, size: 4002, end: 6144 vif vif-3-0 vif3.0: fatal error; disabling device Reported-by: Anthony Wright Tested-by: Anthony Wright Signed-off-by: David Vrabel Signed-off-by: David S. Miller BugLink: http://bugs.launchpad.net/bugs/1317811 Signed-off-by: Stefan Bader Signed-off-by: Kamal Mostafa --- drivers/net/xen-netfront.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index a3ed8de..9f02c5a 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -572,6 +572,9 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) slots, skb->len); if (skb_linearize(skb)) goto drop; + data = skb->data; + offset = offset_in_page(data); + len = skb_headlen(skb); } spin_lock_irqsave(&np->tx_lock, flags); -- 1.9.1