Re: [PATCH] ipv6: del unreachable route when an addr is deleted on lo

When an address is added on loopback (ip -6 a a 2002::1/128 dev lo), two routes
are added:
 - one in the local table:
    local 2002::1 via :: dev lo  proto none  metric 0
 - one the in main table (for the prefix):
    unreachable 2002::1 dev lo  proto kernel  metric 256  error -101

When the address is deleted, the route inserted in the main table remains
because we use rt6_lookup(), which returns NULL when dst->error is set, which
is the case here! Thus, it is better to use ip6_route_lookup() to avoid this
kind of filter.

Signed-off-by: Nicolas Dichtel <redacted>
---
 net/ipv6/addrconf.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6bc85f7..b6b2f9f 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c

@@ -788,8 +788,12 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
 		struct in6_addr prefix;
 		struct rt6_info *rt;
 		struct net *net = dev_net(ifp->idev->dev);
+		struct flowi6 fl6 = {};
 		ipv6_addr_prefix(&prefix, &ifp->addr, ifp->prefix_len);
-		rt = rt6_lookup(net, &prefix, NULL, ifp->idev->dev->ifindex, 1);
+		fl6.flowi6_oif = ifp->idev->dev->ifindex;
+		fl6.daddr = prefix;
+		rt = (struct rt6_info *)ip6_route_lookup(net, &fl6,
+							 RT6_LOOKUP_F_IFACE);