From fe6fe14f1158bbcf4a07240cb93925e84ef25e89 Mon Sep 17 00:00:00 2001
From: Andrey Konovalov <andreyknvl@google.com>
Date: Wed, 29 Mar 2017 16:11:22 +0200
Subject: net/packet: fix overflow in check for tp_reserve

[ Upstream commit bcc5364bdcfe131e6379363f089e7b4108d35b70 ]

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

Fix by checking that tp_reserve <= INT_MAX on assign.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/packet/af_packet.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'net/packet/af_packet.c')

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 9c8021234481..05cfee756898 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3314,6 +3314,8 @@ 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;
 	}
-- 
cgit v1.2.1