ipv4: reset fnhe_mtu_locked after cache route flushed
After route cache is flushed via ipv4_sysctl_rtcache_flush(), we forget
to reset fnhe_mtu_locked in rt_bind_exception(). When pmtu is updated
in __ip_rt_update_pmtu(), it will return directly since the pmtu is
still locked. e.g.
+ ip netns exec client ping 10.10.1.1 -c 1 -s 1400 -M do
PING 10.10.1.1 (10.10.1.1) 1400(1428) bytes of data.
>From 10.10.0.254 icmp_seq=1 Frag needed and DF set (mtu = 0)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 1412a7b..29268ef 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1375,6 +1375,7 @@
fnhe->fnhe_gw = 0;
fnhe->fnhe_pmtu = 0;
fnhe->fnhe_expires = 0;
+ fnhe->fnhe_mtu_locked = false;
fnhe_flush_routes(fnhe);
orig = NULL;
}