diff options
| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2013-09-29 05:40:50 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-09-30 22:04:09 -0700 |
| commit | 3da812d860755925da890e8c713f2d2e2d7b1bae (patch) | |
| tree | 071f33a1289ad20fda51b816d3df6703e37d1866 /net/ipv6 | |
| parent | e58f6f4fb4eada7867014bfaec898f03afbce5c2 (diff) | |
ipv6: gre: correct calculation of max_headroom
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>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/ip6_gre.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 6b26e9feafb9..7bb5446b9d73 100644 --- 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))) { |