Re: [PATCH v2 1/4] scsi: sd: reject invalid pr_read_keys() num_keys values

Stefan Hajnoczi
2025-12-01T16:23:28Z

[-- Attachment #1: Type: text/plain, Size: 726 bytes --]

On Mon, Dec 01, 2025 at 07:34:13AM +0100, Christoph Hellwig wrote:
> On Thu, Nov 27, 2025 at 10:54:21AM -0500, Stefan Hajnoczi wrote:
> > + /*
> > + * Each reservation key takes 8 bytes and there is an 8-byte header
> > + * before the reservation key list. The total size must fit into the
> > + * 16-bit ALLOCATION LENGTH field.
> > + */
> > + if (num_keys > (USHRT_MAX / 8) - 1)
> > + return -EINVAL;
> > +
> > + data_len = num_keys * 8 + 8;
>
> Having the same arithmerics express here in two different ways is a bit
> odd.
>
> I'd expected this to be something like:
>
> if (check_mul_overflow(num_keys, 8, &data_len) || data_len > USHRT_MAX)
> return -EINVAL;

Will fix, thanks.

Stefan

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]