On Tue, Dec 03, 2024 at 11:19:25AM +0300, Dan Carpenter wrote:
> Hello Jeff Layton,
>
> Commit d48464878708 ("ceph: decode interval_sets for delegated inos")
> from Nov 15, 2019 (linux-next), leads to the following Smatch static
> checker warning:
>
> fs/ceph/mds_client.c:644 ceph_parse_deleg_inos()
> warn: potential user controlled sizeof overflow 'sets * 2 * 8' '0-u32max * 8'
>
> fs/ceph/mds_client.c
> 637 static int ceph_parse_deleg_inos(void **p, void *end,
> 638 struct ceph_mds_session *s)
> 639 {
> 640 u32 sets;
> 641
> 642 ceph_decode_32_safe(p, end, sets, bad);
> ^^^^
> set to user data here.
>
> 643 if (sets)
> --> 644 ceph_decode_skip_n(p, end, sets * 2 * sizeof(__le64), bad);
> ^^^^^^^^^^^^^^^^^^^^^^^^^
> This is safe on 64bit but on 32bit systems it can integer overflow/wrap.
>
Smatch has similar warnings in ceph_mdsmap_decode().
fs/ceph/mdsmap.c:228 ceph_mdsmap_decode() warn: potential user controlled sizeof overflow 'num_export_targets * 4' '0-u32max * 4'
fs/ceph/mdsmap.c:280 ceph_mdsmap_decode() warn: potential user controlled sizeof overflow '8 * (n + 1)' '8 * s32min-s32max'
fs/ceph/mdsmap.c:337 ceph_mdsmap_decode() warn: potential user controlled sizeof overflow '4 * n' '4 * 0-u32max'
fs/ceph/mdsmap.c:339 ceph_mdsmap_decode() warn: potential user controlled sizeof overflow '4 * n' '4 * 0-u32max'
regards,
dan carpenter
