Re: [PATCH] mm/migrate_device: fix pgtable leak in migrate_vma_insert_huge_pmd_page

[Sunny Patel <nueralspacetech@gmail.com>]

On Sat, 25 Apr 2026 10:21:01 -0400, Zi Yan wrote:
> I think the "goto abort" above pmd_lock() need to do pte_free():
>
>         if (folio_is_device_private(folio)) {
>                         ...
>         } else {
>                 if (folio_is_zone_device(folio) &&
>                     !folio_is_device_coherent(folio)) {
>                         goto abort; <-- this one
>                 }
>                         ...
>         }
>
> The lock is not taken yet, so you might need to add a pte_free()
> before goto abort.

You are right. The pgtable is allocated before this check and
the lock has not been taken yet at this point, so goto
unlock_abort would be incorrect here. A pte_free() call is
needed before this goto abort.

Sent v2 with the changes.
https://lore.kernel.org/linux-mm/20260427063729.17294-1-nueralspacetech@gmail.com/

Thanks for catching this.

Regards,
Sunny Patel