ip_tunnel: Fix a memory corruption in ip_tunnel_xmit
authorSteffen Klassert <steffen.klassert@secunet.com>
Tue, 1 Oct 2013 09:33:59 +0000 (11:33 +0200)
committerDavid S. Miller <davem@davemloft.net>
Tue, 1 Oct 2013 16:42:16 +0000 (12:42 -0400)
commit3e08f4a72f689c6296d336c2aab4bddd60c93ae2
tree726a51f17de026da0e7c0135f827d529a406fcfd
parente024bdc051ab99eafb5dd9bad87e79afc27f8a44
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>
net/ipv4/ip_tunnel.c