[PATCH 072/102] aoe: reserve enough headroom on skbs

From: Luis Henriques
Date: Mon Apr 08 2013 - 06:02:44 EST


3.5.7.10 -stable review patch. If anyone has any objections, please let me know.

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

From: Eric Dumazet <edumazet@xxxxxxxxxx>

commit 91c5746425aed8f7188a351f1224a26aa232e4b3 upstream.

Some network drivers use a non default hard_header_len

Transmitted skb should take into account dev->hard_header_len, or risk
crashes or expensive reallocations.

In the case of aoe, lets reserve MAX_HEADER bytes.

David reported a crash in defxx driver, solved by this patch.

Reported-by: David Oostdyk <daveo@xxxxxxxxxx>
Tested-by: David Oostdyk <daveo@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Ed Cashin <ecashin@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
drivers/block/aoe/aoecmd.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 887f68f..db30542 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -30,8 +30,9 @@ new_skb(ulong len)
{
struct sk_buff *skb;

- skb = alloc_skb(len, GFP_ATOMIC);
+ skb = alloc_skb(len + MAX_HEADER, GFP_ATOMIC);
if (skb) {
+ skb_reserve(skb, MAX_HEADER);
skb_reset_mac_header(skb);
skb_reset_network_header(skb);
skb->protocol = __constant_htons(ETH_P_AOE);
--
1.8.1.2

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