On Fri, Jun 13, 2025 at 11:27:00AM +0200, David Hildenbrand wrote:
> We setup the cache mode but ... don't forward the updated pgprot to
> insert_pfn_pud().
>
> Only a problem on x86-64 PAT when mapping PFNs using PUDs that
> require a special cachemode.
>
> Fix it by using the proper pgprot where the cachemode was setup.
>
> It is unclear in which configurations we would get the cachemode wrong:
> through vfio seems possible. Getting cachemodes wrong is usually ... bad.
> As the fix is easy, let's backport it to stable.
>
> Identified by code inspection.
>
> Fixes: 7b806d229ef1 ("mm: remove vmf_insert_pfn_xxx_prot() for huge
> page-table entries")
> Reviewed-by: Dan Williams <[email protected]>
> Reviewed-by: Lorenzo Stoakes <[email protected]>
> Reviewed-by: Jason Gunthorpe <[email protected]>
> Tested-by: Dan Williams <[email protected]>
> Cc: <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
--
Oscar Salvador
SUSE Labs
