Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756542Ab2J1XuD (ORCPT ); Sun, 28 Oct 2012 19:50:03 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41787 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756300Ab2J1X1A (ORCPT ); Sun, 28 Oct 2012 19:27:00 -0400 Message-Id: <20121028231542.256308645@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 28 Oct 2012 23:15:53 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, "ramesh.nagappa@gmail.com" , Ramesh Nagappa , Shawn Lu , Robert Coulson , Billie Alsup , "David S. Miller" Subject: [ 017/105] net: Fix skb_under_panic oops in neigh_resolve_output In-Reply-To: <20121028231536.970033833@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2214 Lines: 62 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: "ramesh.nagappa@gmail.com" [ Upstream commit e1f165032c8bade3a6bdf546f8faf61fda4dd01c ] 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 Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/core/neighbour.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 7aafaed..5b9709f 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1254,8 +1254,6 @@ int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb) if (!dst) goto discard; - __skb_pull(skb, skb_network_offset(skb)); - if (!neigh_event_send(neigh, skb)) { int err; struct net_device *dev = neigh->dev; @@ -1265,6 +1263,7 @@ int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb) neigh_hh_init(neigh, dst); do { + __skb_pull(skb, skb_network_offset(skb)); seq = read_seqbegin(&neigh->ha_lock); err = dev_hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, NULL, skb->len); @@ -1295,9 +1294,8 @@ int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb) unsigned int seq; int err; - __skb_pull(skb, skb_network_offset(skb)); - do { + __skb_pull(skb, skb_network_offset(skb)); seq = read_seqbegin(&neigh->ha_lock); err = dev_hard_header(skb, dev, ntohs(skb->protocol), neigh->ha, NULL, skb->len); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/