Re: [PATCH 2/3] iommufd: WARN if an object is aborted with an elevated refcount

Nicolin Chen
2025-09-18T20:50:53Z

On Wed, Sep 17, 2025 at 05:01:48PM -0300, Jason Gunthorpe wrote:
> If something holds a refcount then it is at risk of UAFing. For abort
> paths we expect the caller to never share the object with a parallel
> thread and to clean up any refcounts it obtained on its own.
>
> Add the missing dec inside iommufd_hwpt_paging_alloc()during error unwind
> by making iommufd_hw_pagetable_attach/detach() proper pairs.
>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>