From: Andrey Konovalov <andreyknvl@google.com>
Date: Wed, 29 Mar 2017 14:11:22 +0000 (+0200)
Subject: net/packet: fix overflow in check for tp_reserve
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~10^2~22
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=25adf4e32a890244f4f53d2ab30b423efb5aab41;p=firefly-linux-kernel-4.4.55.git

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>
---

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index b4af3f7b57ab..f8d6a0ca9c03 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3626,6 +3626,8 @@ 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;
 	}