[IPV4]: ip_route_input panic fix (CVE-2006-1525)

commit 4ff1c7d9b24059c758ed4600f35da71a0b11557a
tree d899f9983c5500765b677d419657a75d88fdad40
parent 3bbf58a7d45e5b50d70215c5894aa0438a8f831d
author Stephen Hemminger <[email protected]> Mon, 29 May 2006 13:27:17 -0700
committer David S. Miller <[email protected]> Mon, 29 May 2006 13:27:17 -0700

[IPV4]: ip_route_input panic fix (CVE-2006-1525)

This fixes http://bugzilla.kernel.org/show_bug.cgi?id=6388
The bug is caused by ip_route_input dereferencing skb->nh.protocol of
the dummy skb passed dow from inet_rtm_getroute (Thanks Thomas for seeing
it). It only happens if the route requested is for a multicast IP
address.

Signed-off-by: Stephen Hemminger <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

 net/ipv4/route.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 81e98dc..c125592 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2214,7 +2214,10 @@ int inet_rtm_getroute(struct sk_buff *in
 	/* Reserve room for dummy headers, this skb can pass
 	   through good chunk of routing engine.
 	 */
-	skb->mac.raw = skb->data;
+	skb->mac.raw = skb->nh.raw = skb->data;
+
+	/* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
+	skb->nh.iph->protocol = IPPROTO_ICMP;
 	skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
 
 	if (rta[RTA_SRC - 1])