netfilter: ipset: regression in ip_set_hash_ip.c

This patch introduced a regression: commit 48596a8ddc46 ("netfilter:
ipset: Fix adding an IPv4 range containing more than 2^31 addresses")

The variable e.ip is passed to adtfn() function which finally adds the
ip address to the set. The patch above refactored the for loop and moved
e.ip = htonl(ip) to the end of the for loop.

What this means is that if the value of "ip" changes between the first
assignement of e.ip and the forloop, then e.ip is pointing to a
different ip address than "ip".

Test case:
$ ipset create jdtest_tmp hash:ip family inet hashsize 2048 maxelem 100000
$ ipset add jdtest_tmp 10.0.1.1/31
ipset v6.21.1: Element cannot be added to the set: it's already added

The value of ip gets updated inside the  "else if (tb[IPSET_ATTR_CIDR])"
block but e.ip is still pointing to the old value.

Reviewed-by: Joshua Hunt <johunt@akamai.com>
Signed-off-by: Vishwanath Pai <vpai@akamai.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>

1 files changed, 3 insertions, 5 deletions

diff --git a/kernel/net/netfilter/ipset/ip_set_hash_ip.c b/kernel/net/netfilter/ipset/ip_set_hash_ip.c
index baa5e14..90dfe85 100644
--- a/kernel/net/netfilter/ipset/ip_set_hash_ip.c
+++ b/kernel/net/netfilter/ipset/ip_set_hash_ip.c
@@ -152,18 +152,16 @@ hash_ip4_uadt(struct ip_set *set, struct nlattr *tb[],
 	if (((u64)ip_to - ip + 1) >> (32 - h->netmask) > IPSET_MAX_RANGE)
 		return -ERANGE;
 
-	if (retried) {
+	if (retried)
 		ip = ntohl(h->next.ip);
-		e.ip = htonl(ip);
-	}
 	for (; ip <= ip_to;) {
+		e.ip = htonl(ip);
 		ret = adtfn(set, &e, &ext, &ext, flags);
 		if (ret && !ip_set_eexist(ret, flags))
 			return ret;
 
 		ip += hosts;
-		e.ip = htonl(ip);
-		if (e.ip == 0)
+		if (ip == 0)
 			return 0;
 
 		ret = 0;