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| author | Steffen Klassert <steffen.klassert@secunet.com> | 2013-10-01 11:33:59 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-10-01 18:42:16 +0200 |
| commit | 3e08f4a72f689c6296d336c2aab4bddd60c93ae2 (patch) | |
| tree | 726a51f17de026da0e7c0135f827d529a406fcfd | |
| parent | Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf (diff) | |
| download | linux-3e08f4a72f689c6296d336c2aab4bddd60c93ae2.tar.xz linux-3e08f4a72f689c6296d336c2aab4bddd60c93ae2.zip | |
ip_tunnel: Fix a memory corruption in ip_tunnel_xmit
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>
| -rw-r--r-- | net/ipv4/ip_tunnel.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index d3fbad422e0e..dfc6d8a3caa7 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -642,13 +642,13 @@ 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(rt, skb, fl4.saddr, fl4.daddr, protocol, |