aoe: reserve enough headroom on skbs

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@ll.mit.edu>
Tested-by: David Oostdyk <daveo@ll.mit.edu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ed Cashin <ecashin@coraid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 25ef5c0..92b6d7c 100644 (file)
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -51,8 +51,9 @@ 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);