From: Jozsef Kadlecsik <kadlec@netfilter.org>
Date: Wed, 28 Jul 2021 14:06:46 +0000 (+0200)
Subject: 64bit division isn't allowed on 32bit, replace it with shift
X-Git-Tag: v7.14~1
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=73e5366e2295f009da5ac3fd608dfe8464c795d3;p=thirdparty%2Fipset.git

64bit division isn't allowed on 32bit, replace it with shift

The number of hosts in a netblock must be a power of two,
so use shift instead of division.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
---

diff --git a/kernel/net/netfilter/ipset/ip_set_hash_ip.c b/kernel/net/netfilter/ipset/ip_set_hash_ip.c
index 789b28a4..baa5e14c 100644
--- a/kernel/net/netfilter/ipset/ip_set_hash_ip.c
+++ b/kernel/net/netfilter/ipset/ip_set_hash_ip.c
@@ -148,7 +148,8 @@ hash_ip4_uadt(struct ip_set *set, struct nlattr *tb[],
 
 	hosts = h->netmask == 32 ? 1 : 2 << (32 - h->netmask - 1);
 
-	if (((u64)ip_to - ip + 1)/hosts > IPSET_MAX_RANGE)
+	/* 64bit division is not allowed on 32bit */
+	if (((u64)ip_to - ip + 1) >> (32 - h->netmask) > IPSET_MAX_RANGE)
 		return -ERANGE;
 
 	if (retried) {