[11/27] gro: reset vlan_tci on reuse

From: Greg KH
Date: Wed Dec 07 2011 - 12:02:59 EST


2.6.32-longterm review patch. If anyone has any objections, please let me know.

------------------

This one liner is part of upstream
commit 3701e51382a026cba10c60b03efabe534fba4ca4
Author: Jesse Gross <jesse@xxxxxxxxxx>

vlan: Centralize handling of hardware acceleration.

The bulk of that commit is a rework of the hardware assisted vlan tagging
driver interface, and as such doesn't classify for -stable inclusion. The fix
that is needed is a part of that commit but can work independently of the
rest.

This patch can avoid panics on the 2.6.32.y -stable kernels and is in the same
spirit as mainline commits
66c46d7 gro: Reset dev pointer on reuse
6d152e2 gro: reset skb_iif on reuse
which are already in -stable.

For drivers using the vlan_gro_frags() interface, a packet with an invalid tci
leads to GRO_DROP and napi_reuse_skb(). The skb has to be sanitized before
being reused or we may send an skb with an invalid vlan_tci field up the stack
where it is not expected.

Signed-off-by: Benjamin Poirier <bpoirier@xxxxxxx>
Cc: Jesse Gross <jesse@xxxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>

---
net/core/dev.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2614,6 +2614,7 @@ void napi_reuse_skb(struct napi_struct *
{
__skb_pull(skb, skb_headlen(skb));
skb_reserve(skb, NET_IP_ALIGN - skb_headroom(skb));
+ skb->vlan_tci = 0;
skb->dev = napi->dev;
skb->iif = 0;



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/