netfilter: nf_conncount: don't skip eviction when age is negative

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@cloudflare.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[mfo: backport: use older file name, nf_conncount.c -> xt_connlimit.c]
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index 913b86ef3a8d70004efec9857d233c16f5a4fdfd..b1646c24a632672b1e475d7c0a77ccd509dfd6f6 100644 (file)
--- 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)