4.9-stable review patch. If anyone has any objections, please let me know.
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From: Xin Long lucien.xin@gmail.com
[ Upstream commit cebe84c6190d741045a322f5343f717139993c08 ]
Now when ip route flush cache and it turn out all fnhe_genid != genid. If a redirect/pmtu icmp packet comes and the old fnhe is found and all it's members but fnhe_genid will be updated.
Then next time when it looks up route and tries to rebind this fnhe to the new dst, the fnhe will be flushed due to fnhe_genid != genid. It causes this redirect/pmtu icmp packet acutally not to be applied.
This patch is to also reset fnhe_genid when updating a route cache.
Fixes: 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions") 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 Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/route.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
--- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -630,9 +630,12 @@ static void update_or_create_fnhe(struct struct fnhe_hash_bucket *hash; struct fib_nh_exception *fnhe; struct rtable *rt; + u32 genid, hval; unsigned int i; int depth; - u32 hval = fnhe_hashfun(daddr); + + genid = fnhe_genid(dev_net(nh->nh_dev)); + hval = fnhe_hashfun(daddr);
spin_lock_bh(&fnhe_lock);
@@ -655,6 +658,8 @@ static void update_or_create_fnhe(struct }
if (fnhe) { + if (fnhe->fnhe_genid != genid) + fnhe->fnhe_genid = genid; if (gw) fnhe->fnhe_gw = gw; if (pmtu) { @@ -679,7 +684,7 @@ static void update_or_create_fnhe(struct fnhe->fnhe_next = hash->chain; rcu_assign_pointer(hash->chain, fnhe); } - fnhe->fnhe_genid = fnhe_genid(dev_net(nh->nh_dev)); + fnhe->fnhe_genid = genid; fnhe->fnhe_daddr = daddr; fnhe->fnhe_gw = gw; fnhe->fnhe_pmtu = pmtu;