From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 23 Jan 2012 05:38:59 +0000 (+0000)
Subject: macvlan: fix a possible use after free
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4ec7ac1203bcf21f5e3d977c9818b1a56c9ef40d;p=linux.git

macvlan: fix a possible use after free

Commit bc416d9768 (macvlan: handle fragmented multicast frames) added a
possible use after free in macvlan_handle_frame(), since
ip_check_defrag() uses pskb_may_pull() : skb header can be reallocated.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index f2f820c4b40a4..9ea99217f1160 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -173,6 +173,7 @@ static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
 		skb = ip_check_defrag(skb, IP_DEFRAG_MACVLAN);
 		if (!skb)
 			return RX_HANDLER_CONSUMED;
+		eth = eth_hdr(skb);
 		src = macvlan_hash_lookup(port, eth->h_source);
 		if (!src)
 			/* frame comes from an external address */