[PATCH 14/17] [AF_NETLINK]: Fix DoS in netlink_rcv_skb() (CVE-2006-0035)

[Chris Wright <chrisw@sous-sol.org>]

-stable review patch.  If anyone has any objections, please let us know.
------------------

Sanity check nlmsg_len during netlink_rcv_skb.  An nlmsg_len == 0 can
cause infinite loop in kernel, effectively DoSing machine.  Noted by
Matin Murray.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/netlink/af_netlink.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-2.6.15.y.orig/net/netlink/af_netlink.c
+++ linux-2.6.15.y/net/netlink/af_netlink.c
@@ -1422,7 +1422,7 @@ static int netlink_rcv_skb(struct sk_buf
 	while (skb->len >= nlmsg_total_size(0)) {
 		nlh = (struct nlmsghdr *) skb->data;
 
-		if (skb->len < nlh->nlmsg_len)
+		if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
 			return 0;
 
 		total_len = min(NLMSG_ALIGN(nlh->nlmsg_len), skb->len);

--
-
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