[PATCH 4.20 007/111] netfilter: nf_conncount: dont skip eviction when age is negative

From: Greg Kroah-Hartman
Date: Mon Jan 21 2019 - 09:21:32 EST


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

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

From: Florian Westphal <fw@xxxxxxxxx>

commit 4cd273bb91b3001f623f516ec726c49754571b1a upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/netfilter/nf_conncount.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -155,7 +155,7 @@ find_or_evict(struct net *net, struct nf
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)