ipv6: gre: correct calculation of max_headroom

[~andy/linux] / net / ipv6 / ip6_gre.c

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 6b26e9feafb98eb8d269f553cbf8339a3341526b..7bb5446b9d73c16a7f4096f2705ce60f997c7c2a 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -618,7 +618,7 @@ static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
        struct ip6_tnl *tunnel = netdev_priv(dev);
        struct net_device *tdev;    /* Device to other host */
        struct ipv6hdr  *ipv6h;     /* Our new IP header */
-       unsigned int max_headroom;  /* The extra header space needed */
+       unsigned int max_headroom = 0; /* The extra header space needed */
        int    gre_hlen;
        struct ipv6_tel_txoption opt;
        int    mtu;
@@ -693,7 +693,7 @@ static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 
        skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 
-       max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
+       max_headroom += LL_RESERVED_SPACE(tdev) + gre_hlen + dst->header_len;
 
        if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
            (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {