From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, David Ahern <dsahern@kernel.org>,
        Nicolas Dichtel <nicolas.dichtel@6wind.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 16/21] ipv6: Do cleanup if attribute validation fails in multipath route
Date:   Mon, 10 Jan 2022 08:23:17 +0100
Message-Id: <20220110071814.479947128@linuxfoundation.org>
In-Reply-To: <20220110071813.967414697@linuxfoundation.org>
References: <20220110071813.967414697@linuxfoundation.org>
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From: David Ahern <dsahern@kernel.org>

[ Upstream commit 95bdba23b5b4aa75fe3e6c84335e638641c707bb ]

As Nicolas noted, if gateway validation fails walking the multipath
attribute the code should jump to the cleanup to free previously
allocated memory.

Fixes: 1ff15a710a86 ("ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route")
Signed-off-by: David Ahern <dsahern@kernel.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20220103170555.94638-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ipv6/route.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 8a437c20eeccd..7e3ab23fc995c 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -4466,12 +4466,10 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
 
 			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
 			if (nla) {
-				int ret;
-
-				ret = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
+				err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
 							extack);
-				if (ret)
-					return ret;
+				if (err)
+					goto cleanup;
 
 				r_cfg.fc_flags |= RTF_GATEWAY;
 			}
-- 
2.34.1