Subject: [PATCH net 4/5] ipv6: Check attribute length for RTA_GATEWAY when deleting multipath route

From: David Ahern <[email-masked]>
Date: Thu, 30 Dec 2021 17:36:34 -0700

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 <[email-masked]>
Cc: Roopa Prabhu <[email-masked]>
---
 net/ipv6/route.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d16599c225b8..b311c0bc9983 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -5453,7 +5453,11 @@ 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;
 			}
 		}
-- 
2.24.3 (Apple Git-128)