From patchwork Thu Dec 13 13:59:01 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [176/241] net: Fix skb_under_panic oops in neigh_resolve_output Date: Thu, 13 Dec 2012 03:59:01 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 206022 Message-Id: <1355407206-17100-177-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Ramesh Nagappa , "David S. Miller" 3.5.7.2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: "ramesh.nagappa@gmail.com" commit e1f165032c8bade3a6bdf546f8faf61fda4dd01c upstream. 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: Herton Ronaldo Krzesinski --- 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 d81d026..5c2dac3 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1286,8 +1286,6 @@ 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; @@ -1297,6 +1295,7 @@ 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); @@ -1327,9 +1326,8 @@ 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);