From: Martin Murray <murrayma@citi.umich.edu>
Date: Tue, 10 Jan 2006 21:02:29 +0000 (-0800)
Subject: [AF_NETLINK]: Fix DoS in netlink_rcv_skb()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ad8e4b75c8a7bed475d72ce09bf5267188621961;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

[AF_NETLINK]: Fix DoS in netlink_rcv_skb()

From: Martin Murray <murrayma@citi.umich.edu>

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>
---

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a67f1b44c9a..bb50c8a9fca 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1422,7 +1422,7 @@ static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
 	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);