4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xin Long <lucien.xin@xxxxxxxxx>
[ 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@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;