On Wed, Aug 13 2025, Greg KH wrote:
> On Tue, Aug 12, 2025 at 11:34:37PM -0700, Vipin Sharma wrote:
>> On 2025-08-07 01:44:35, Pasha Tatashin wrote:
>> > From: Pratyush Yadav <ptyadav@xxxxxxxxx>
>> > +static void memfd_luo_unpreserve_folios(const struct memfd_luo_preserved_folio *pfolios,
>> > + unsigned int nr_folios)
>> > +{
>> > + unsigned int i;
>> > +
>> > + for (i = 0; i < nr_folios; i++) {
>> > + const struct memfd_luo_preserved_folio *pfolio = &pfolios[i];
>> > + struct folio *folio;
>> > +
>> > + if (!pfolio->foliodesc)
>> > + continue;
>> > +
>> > + folio = pfn_folio(PRESERVED_FOLIO_PFN(pfolio->foliodesc));
>> > +
>> > + kho_unpreserve_folio(folio);
>>
>> This one is missing WARN_ON_ONCE() similar to the one in
>> memfd_luo_preserve_folios().
>
> So you really want to cause a machine to reboot and get a CVE issued for
> this, if it could be triggered? That's bold :)
>
> Please don't. If that can happen, handle the issue and move on, don't
> crash boxes.
Why would a WARN() crash the machine? That is what BUG() does, not
WARN().
--
Regards,
Pratyush Yadav
