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authorSteffen Klassert <steffen.klassert@secunet.com>2013-10-01 11:33:59 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-13 18:14:26 -0700
commit0accb77476d803ae62f2519c04e32f9eb2495698 (patch)
tree3f55a9a083d64599801977f824fedc7d15248e0a /net
parenteeb6df7a3b949813f257680802fda8dd4a3996ab (diff)
ip_tunnel: Fix a memory corruption in ip_tunnel_xmit
[ Upstream commit 3e08f4a72f689c6296d336c2aab4bddd60c93ae2 ] We might extend the used aera of a skb beyond the total headroom when we install the ipip header. Fix this by calling skb_cow_head() unconditionally. Bug was introduced with commit c544193214 ("GRE: Refactor GRE tunneling code.") Cc: Pravin Shelar <pshelar@nicira.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.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/ipv4/ip_tunnel.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index bb7cf056458..ffc21083094 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -645,13 +645,13 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr)
+ rt->dst.header_len;
- if (max_headroom > dev->needed_headroom) {
+ if (max_headroom > dev->needed_headroom)
dev->needed_headroom = max_headroom;
- if (skb_cow_head(skb, dev->needed_headroom)) {
- dev->stats.tx_dropped++;
- dev_kfree_skb(skb);
- return;
- }
+
+ if (skb_cow_head(skb, dev->needed_headroom)) {
+ dev->stats.tx_dropped++;
+ dev_kfree_skb(skb);
+ return;
}
err = iptunnel_xmit(dev_net(dev), rt, skb,