Hello Jeongjun,

On Tue, 12 Nov 2024, Jeongjun Park wrote:

In the bitmap_ip_uadt function, if ip is greater than ip_to, they are swapped. However, there is no check to see if ip is smaller than map->first, which causes an out-of-bounds vulnerability. Therefore, you need to add a missing bounds check to prevent out-of-bounds.

It's a good catch, thanks! However, with the patch below the

if (ip < map->first_ip) return -IPSET_ERR_BITMAP_RANGE;

lines in the branch just after swapping the from/to addresses becomes unnecessary. Could you send a second version of the patch with the lines above removed?

Best regards, Jozsef

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

---

net/netfilter/ipset/ip_set_bitmap_ip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/ipset/ip_set_bitmap_ip.c b/net/netfilter/ipset/ip_set_bitmap_ip.c index e4fa00abde6a..705c316b001a 100644 --- a/net/netfilter/ipset/ip_set_bitmap_ip.c +++ b/net/netfilter/ipset/ip_set_bitmap_ip.c @@ -178,7 +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) { --