From: David Ahern <dsahern@kernel.org>
Date: Fri, 31 Dec 2021 00:36:34 +0000 (-0700)
Subject: ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route
X-Git-Tag: v4.19.225~13
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e30dead00aaa5a575b10117dad8edc126efc1873;p=users%2Fdwmw2%2Flinux.git

ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route

commit 1ff15a710a862db1101b97810af14aedc835a86a upstream.

Make sure RTA_GATEWAY for IPv6 multipath route has enough bytes to hold
an IPv6 address.

Fixes: 6b9ea5a64ed5 ("ipv6: fix multipath route replace error recovery")
Signed-off-by: David Ahern <dsahern@kernel.org>
Cc: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 9df115e89f6ca..1bc81be07ccda 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -4606,7 +4606,11 @@ static int ip6_route_multipath_del(struct fib6_config *cfg,
 
 			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
 			if (nla) {
-				nla_memcpy(&r_cfg.fc_gateway, nla, 16);
+				err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
+							extack);
+				if (err)
+					return err;
+
 				r_cfg.fc_flags |= RTF_GATEWAY;
 			}
 		}