route: update fnhe_expires for redirect when the fnhe exists

Now when creating fnhe for redirect, it sets fnhe_expires for this
new route cache. But when updating the exist one, it doesn't do it.
It will cause this fnhe never to be expired.

Paolo already noticed it before, in Jianlin's test case, it became
even worse:

When ip route flush cache, the old fnhe is not to be removed, but
only clean it's members. When redirect comes again, this fnhe will
be found and updated, but never be expired due to fnhe_expires not
being set.

So fix it by simply updating fnhe_expires even it's for redirect.

Fixes: 69909d91bfcf ("ipv4: use seqlock for nh_exceptions")
Reported-by: Jianlin Shi <jishi@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 3b427757b1f8ecfee63c0f0667dfa0c38c1653ae..11cf2fe4330867062eedffce714d85b98cd1a3e6 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -678,10 +678,9 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw,
        if (fnhe) {
                if (gw)
                        fnhe->fnhe_gw = gw;
-               if (pmtu) {
+               if (pmtu)
                        fnhe->fnhe_pmtu = pmtu;
-                       fnhe->fnhe_expires = max(1UL, expires);
-               }
+               fnhe->fnhe_expires = max(1UL, expires);
                /* Update all cached dsts too */
                rt = rcu_dereference(fnhe->fnhe_rth_input);
                if (rt)