netfilter: ipset: add missing range check in bitmap_ip_uadt

When tb[IPSET_ATTR_IP_TO] is not present but tb[IPSET_ATTR_CIDR] exists,
the values of ip and ip_to are slightly swapped. Therefore, the range check
for ip should be done later, but this part is missing and it seems that the
vulnerability occurs.

So we should add missing range checks and remove unnecessary range checks.

Cc: <stable@vger.kernel.org>
Reported-by: syzbot+58c872f7790a4d2ac951@syzkaller.appspotmail.com
Fixes: 72205fc68bd1 ("netfilter: ipset: bitmap:ip set type support")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/ipset/ip_set_bitmap_ip.c b/net/netfilter/ipset/ip_set_bitmap_ip.c
index e4fa00abde6a2ab9941c8cd7d0b8a12f537503e0..5988b9bb9029dc1ac6e3c88d79c9d74442e00ac4 100644 (file)
--- a/net/netfilter/ipset/ip_set_bitmap_ip.c
+++ b/net/netfilter/ipset/ip_set_bitmap_ip.c
@@ -163,11 +163,8 @@ bitmap_ip_uadt(struct ip_set *set, struct nlattr *tb[],
                ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
                if (ret)
                        return ret;
-               if (ip > ip_to) {
+               if (ip > ip_to)
                        swap(ip, ip_to);
-                       if (ip < map->first_ip)
-                               return -IPSET_ERR_BITMAP_RANGE;
-               }
        } else if (tb[IPSET_ATTR_CIDR]) {
                u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
 
@@ -178,7 +175,7 @@ bitmap_ip_uadt(struct ip_set *set, struct nlattr *tb[],
                ip_to = ip;
        }
 
-       if (ip_to > map->last_ip)
+       if (ip < map->first_ip || ip_to > map->last_ip)
                return -IPSET_ERR_BITMAP_RANGE;
 
        for (; !before(ip_to, ip); ip += map->hosts) {