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authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-09-29 05:40:50 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-13 16:08:30 -0700
commit102ce961c8d54d613eb49d6bc71ecec674505815 (patch)
treee7f6efe877f1477b8e81878dd06ba2f3f1880407 /net
parentc9b391f6d166118c5543e9d1708e67977dbdbe1f (diff)
downloadvexpress-lsk-102ce961c8d54d613eb49d6bc71ecec674505815.tar.gz
ipv6: gre: correct calculation of max_headroom
[ Upstream commit 3da812d860755925da890e8c713f2d2e2d7b1bae ] gre_hlen already accounts for sizeof(struct ipv6_hdr) + gre header, so initialize max_headroom to zero. Otherwise the if (encap_limit >= 0) { max_headroom += 8; mtu -= 8; } increments an uninitialized variable before max_headroom was reset. Found with coverity: 728539 Cc: Dmitry Kozlov <xeb@mail.ru> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv6/ip6_gre.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index ecd60733e5e..1f9a1a5b61f 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -620,7 +620,7 @@ 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,
tunnel->err_count = 0;
}
- 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))) {