[PATCH 4.14 084/101] netfilter: nf_conncount: dont skip eviction when age is negative

From: Greg Kroah-Hartman
Date: Mon Jan 07 2019 - 08:04:37 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

commit 4cd273bb91b3001f623f516ec726c49754571b1a upstream.

(not in Linus's tree now, but in nf.git + linux-next.git already.)

age is signed integer, so result can be negative when the timestamps
have a large delta. In this case we want to discard the entry.

Instead of using age >= 2 || age < 0, just make it unsigned.

Fixes: b36e4523d4d56 ("netfilter: nf_conncount: fix garbage collection confirm race")
Reviewed-by: Shawn Bohrer <sbohrer@xxxxxxxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>

[mfo: backport: use older file name, nf_conncount.c -> xt_connlimit.c]
Signed-off-by: Mauricio Faria de Oliveira <mfo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/netfilter/xt_connlimit.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index 913b86ef3a8d..b1646c24a632 100644
--- a/net/netfilter/xt_connlimit.c
+++ b/net/netfilter/xt_connlimit.c
@@ -141,7 +141,7 @@ find_or_evict(struct net *net, struct xt_connlimit_conn *conn)
const struct nf_conntrack_tuple_hash *found;
unsigned long a, b;
int cpu = raw_smp_processor_id();
- __s32 age;
+ u32 age;

found = nf_conntrack_find_get(net, &conn->zone, &conn->tuple);
if (found)
--
2.19.1