From ad69147ee98365e159072b36b951662b7a849b6a Mon Sep 17 00:00:00 2001
From: Andrey Konovalov <andreyknvl@google.com>
Date: Wed, 29 Mar 2017 16:11:22 +0200
Subject: [PATCH] net/packet: fix overflow in check for tp_reserve

When calculating po->tp_hdrlen + po->tp_reserve the result can overflow.

Fix by checking that tp_reserve <= INT_MAX on assign.

Change-Id: If3b5fd73bd440de2a1050644b71ef7430f09810f
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-commit: bcc5364bdcfe131e6379363f089e7b4108d35b70
Signed-off-by: Dennis Cagle <dcagle@codeaurora.org>
---
 net/packet/af_packet.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index d564572adf80..981579212a96 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3602,6 +3602,8 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
 			return -EBUSY;
 		if (copy_from_user(&val, optval, sizeof(val)))
 			return -EFAULT;
+		if (val > INT_MAX)
+			return -EINVAL;
 		po->tp_reserve = val;
 		return 0;
 	}