ipv4: fix a potential use after free in ip_tunnel_core.c
pskb_may_pull() maybe change skb->data and make eth pointer oboslete,
so set eth after pskb_may_pull()
Fixes:3d7b46cd("ip_tunnel: push generic protocol handling to ip_tunnel module")
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index f4c987b..88c386c 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -91,11 +91,12 @@
skb_pull_rcsum(skb, hdr_len);
if (inner_proto == htons(ETH_P_TEB)) {
- struct ethhdr *eh = (struct ethhdr *)skb->data;
+ struct ethhdr *eh;
if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
return -ENOMEM;
+ eh = (struct ethhdr *)skb->data;
if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN))
skb->protocol = eh->h_proto;
else