From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751089Ab2JEDGL (ORCPT ); Thu, 4 Oct 2012 23:06:11 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:47196 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750817Ab2JEDGJ (ORCPT ); Thu, 4 Oct 2012 23:06:09 -0400 From: ramesh.nagappa@gmail.com To: bnramesh@yahoo.com Cc: davem@davemloft.net, edumazet@google.com, ebiederm@xmission.com, xemul@parallels.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Ramesh Nagappa Subject: [PATCH] net: Fix skb_under_panic oops in neigh_resolve_output Date: Thu, 4 Oct 2012 20:05:25 -0700 Message-Id: <1349406325-3157-1-git-send-email-ramesh.nagappa@gmail.com> X-Mailer: git-send-email 1.7.11.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ramesh Nagappa The retry loop in neigh_resolve_output() and neigh_connected_output() call dev_hard_header() with out reseting the skb to network_header. This causes the retry to fail with skb_under_panic. The fix is to reset the network_header within the retry loop. Signed-off-by: Ramesh Nagappa Reviewed-by: Shawn Lu Reviewed-by: Robert Coulson Reviewed-by: Billie Alsup --- net/core/neighbour.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 117afaf..f50c542 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1313,6 +1313,7 @@ int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb) do { seq = read_seqbegin(&neigh->ha_lock); + __skb_pull(skb, skb_network_offset(skb)); err = dev_hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, NULL, skb->len); } while (read_seqretry(&neigh->ha_lock, seq)); @@ -1342,10 +1343,9 @@ int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb) unsigned int seq; int err; - __skb_pull(skb, skb_network_offset(skb)); - do { seq = read_seqbegin(&neigh->ha_lock); + __skb_pull(skb, skb_network_offset(skb)); err = dev_hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, NULL, skb->len); } while (read_seqretry(&neigh->ha_lock, seq)); -- 1.7.11.4