vxlan: using pskb_may_pull as early as possible

[ 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@gmail.com>
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 3e35bc6..e1b4e00 100644 (file)
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1447,9 +1447,6 @@ 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;
@@ -1979,7 +1976,8 @@ 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;