[PATCH 3.12 009/206] vxlan: using pskb_may_pull as early as possible

From: Jiri Slaby
Date: Tue Nov 18 2014 - 10:25:53 EST


From: Li RongQing <roy.qing.li@xxxxxxxxx>

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

===============

[ Upstream commit 91269e390d062b526432f2ef1352b8df82e0e0bc ]

pskb_may_pull should be used to check if skb->data has enough space,
skb->len can not ensure that.

Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Signed-off-by: Li RongQing <roy.qing.li@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
---
drivers/net/vxlan.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 637e5ad186ef..aff1694d2d9e 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1341,9 +1341,6 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb)
if (!in6_dev)
goto out;

- if (!pskb_may_pull(skb, skb->len))
- goto out;
-
iphdr = ipv6_hdr(skb);
saddr = &iphdr->saddr;
daddr = &iphdr->daddr;
@@ -1890,7 +1887,8 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
return arp_reduce(dev, skb);
#if IS_ENABLED(CONFIG_IPV6)
else if (ntohs(eth->h_proto) == ETH_P_IPV6 &&
- skb->len >= sizeof(struct ipv6hdr) + sizeof(struct nd_msg) &&
+ pskb_may_pull(skb, sizeof(struct ipv6hdr)
+ + sizeof(struct nd_msg)) &&
ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
struct nd_msg *msg;

--
2.1.3

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