netfilter: ipset: add missing range check in bitmap_ip_uadt

commit 35f56c554eb1b56b77b3cf197a6b00922d49033d upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/netfilter/ipset/ip_set_bitmap_ip.c b/net/netfilter/ipset/ip_set_bitmap_ip.c
index 1b9df64c62360af9fcdae8586181b3c95aecbfec..b3ca8e87f629284625c5cfbd6b316590739751ec 100644 (file)
--- a/net/netfilter/ipset/ip_set_bitmap_ip.c
+++ b/net/netfilter/ipset/ip_set_bitmap_ip.c
@@ -166,11 +166,8 @@ 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]);
 
@@ -181,7 +178,7 @@ 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) {