From b317d53680b149e2f1177ceb893a20eeea5a4413 Mon Sep 17 00:00:00 2001
From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Date: Thu, 20 Oct 2022 12:09:52 +0200
Subject: [PATCH] nh: fix scope used to find saddr when adding non gw nh

[ Upstream commit bac0f937c343d651874f83b265ca8f5070ed4f06 ]

As explained by Julian, fib_nh_scope is related to fib_nh_gw4, but
fib_info_update_nhc_saddr() needs the scope of the route, which is
the scope "before" fib_nh_scope, ie fib_nh_scope - 1.

This patch fixes the problem described in commit 747c14307214 ("ip: fix
dflt addr selection for connected nexthop").

Fixes: 597cfe4fc339 ("nexthop: Add support for IPv4 nexthops")
Link: https://lore.kernel.org/netdev/6c8a44ba-c2d5-cdf-c5c7-5baf97cba38@ssi.bg/
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/ipv4/nexthop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index cc8f120149f6b..6cc7d347ec0ad 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -2535,7 +2535,7 @@ static int nh_create_ipv4(struct net *net, struct nexthop *nh,
 	if (!err) {
 		nh->nh_flags = fib_nh->fib_nh_flags;
 		fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
-					  fib_nh->fib_nh_scope);
+					  !fib_nh->fib_nh_scope ? 0 : fib_nh->fib_nh_scope - 1);
 	} else {
 		fib_nh_release(net, fib_nh);
 	}
-- 
2.30.2