When the 'ignore_routes_with_linkdown' sysctl is set, we should not
consider linkdown nexthops during route lookup.
While the code correctly verifies that the initially selected route
('match') has a carrier, it does not perform the same check in the
subsequent multipath selection, resulting in a potential packet loss.
In case the chosen route does not have a carrier and the sysctl is set,
choose the initially selected route.
Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop
link is down")
Signed-off-by: Ido Schimmel <[email protected]>
---
net/ipv6/route.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 05eb7bc36156..0363db914c7a 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -472,6 +472,11 @@ static struct rt6_info *rt6_multipath_select(struct
rt6_info *match,
&match->rt6i_siblings, rt6i_siblings) {
route_choosen--;
if (route_choosen == 0) {
+ struct inet6_dev *idev = sibling->rt6i_idev;
+
+ if (!netif_carrier_ok(sibling->dst.dev) &&
+ idev->cnf.ignore_routes_with_linkdown)
+ break;
if (rt6_score_route(sibling, oif, strict) < 0)
break;
match = sibling;
--
2.14.3
