From: Xin Long <lucien.xin@xxxxxxxxx> This patch has been added to the stable tree. If you have any objections, please let us know. =============== [ Upstream commit e39d5246111399dbc6e11cd39fd8580191b86c47 ] 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: aee06da6726d ("ipv4: use seqlock for nh_exceptions") Reported-by: Jianlin Shi <jishi@xxxxxxxxxx> Acked-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- net/ipv4/route.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 42c7fed200b2..6a9a495aff23 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -654,10 +654,9 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, fnhe->fnhe_genid = genid; 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) -- 2.11.0