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From 04a4af334b971814eedf4e4a413343ad3287d9a9 Mon Sep 17 00:00:00 2001
From: Ross Lagerwall <ross.lagerwall@citrix.com>
Date: Mon, 14 Jan 2019 09:16:56 +0000
Subject: [PATCH] openvswitch: Avoid OOB read when parsing flow nlattrs
Git-commit: 04a4af334b971814eedf4e4a413343ad3287d9a9
Patch-mainline: v5.0-rc3
References: bsc#1051510

For nested and variable attributes, the expected length of an attribute
is not known and marked by a negative number.  This results in an OOB
read when the expected length is later used to check if the attribute is
all zeros. Fix this by using the actual length of the attribute rather
than the expected length.

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/openvswitch/flow_netlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 435a4bdf8f89..691da853bef5 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -500,7 +500,7 @@ static int __parse_flow_nlattrs(const struct nlattr *attr,
 			return -EINVAL;
 		}
 
-		if (!nz || !is_all_zero(nla_data(nla), expected_len)) {
+		if (!nz || !is_all_zero(nla_data(nla), nla_len(nla))) {
 			attrs |= 1 << type;
 			a[type] = nla;
 		}
-- 
2.16.4