From: Mariusz Kozlowski <mk@lab.zgora.pl>
Date: Mon, 8 Nov 2010 11:58:45 +0000 (+0000)
Subject: net: Fix header size check for GSO case in recvmsg (af_packet)
X-Git-Tag: v2.6.36.3~76
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8cd7b4be422ff636fb4359a77c437a214c6f272f;p=karo-tx-linux.git

net: Fix header size check for GSO case in recvmsg (af_packet)

[ Upstream commit 1f18b7176e2e41fada24584ce3c80e9abfaca52b]

Parameter 'len' is size_t type so it will never get negative.

Signed-off-by: Mariusz Kozlowski <mk@lab.zgora.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 9a17f28b1253..c615b0f73b92 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1610,9 +1610,11 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
 
 		err = -EINVAL;
 		vnet_hdr_len = sizeof(vnet_hdr);
-		if ((len -= vnet_hdr_len) < 0)
+		if (len < vnet_hdr_len)
 			goto out_free;
 
+		len -= vnet_hdr_len;
+
 		if (skb_is_gso(skb)) {
 			struct skb_shared_info *sinfo = skb_shinfo(skb);