[SRU C, D/Unstable][PATCH 1/1] netfilter: nf_conncount: don't skip eviction when age is negative

[Mauricio Faria de Oliveira]

From: Florian Westphal <fw at strlen.de>

BugLink: https://bugs.launchpad.net/bugs/1811094

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 at cloudflare.com>
Signed-off-by: Florian Westphal <fw at strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
(cherry picked from commit 4cd273bb91b3001f623f516ec726c49754571b1a)
Signed-off-by: Mauricio Faria de Oliveira <mfo at canonical.com>
---
 net/netfilter/nf_conncount.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c
index 510039862aa9..79d1e17a39d8 100644
--- a/net/netfilter/nf_conncount.c
+++ b/net/netfilter/nf_conncount.c
@@ -106,7 +106,7 @@ find_or_evict(struct net *net, struct nf_conncount_tuple *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)
-- 
2.17.1