Re: [PATCH 1/2] drm/amdgpu: Prevent debugfs nullptr dereference

[Alex Deucher]

Reviewed and applied the series.

Thanks!

Alex

On Wed, Oct 28, 2026 at 9:06 AM Amadeusz Sławiński <amade@xxxxxxxxxx> wrote:
>
> Running
> cat /sys/kernel/debug/dri/0/psp_spirom_dump
> with amdgpu card that doesn't support it leads to nullptr dereference.
> Add checks to prevent that.
>
> Signed-off-by: Amadeusz Sławiński <amade@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 6 ++++++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h | 2 +-
>  2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> index 82a2684dbd2e..627c74f16914 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
> @@ -5381,6 +5381,9 @@ static int psp_read_spirom_debugfs_open(struct inode *inode, struct file *filp)
>         struct spirom_bo *bo_triplet;
>         int ret;
>
> +       if (!adev->psp.funcs || !adev->psp.funcs->dump_spirom)
> +               return -EOPNOTSUPP;
> +
>         /* serialize the open() file calling */
>         if (!mutex_trylock(&adev->psp.mutex))
>                 return -EBUSY;
> @@ -5473,6 +5476,9 @@ void amdgpu_psp_debugfs_init(struct amdgpu_device *adev)
>  #if defined(CONFIG_DEBUG_FS)
>         struct drm_minor *minor = adev_to_drm(adev)->primary;
>
> +       if (!adev->psp.funcs || !adev->psp.funcs->dump_spirom)
> +               return;
> +
>         debugfs_create_file_size("psp_spirom_dump", 0444, minor->debugfs_root,
>                                  adev, &psp_dump_spirom_debugfs_ops, AMD_VBIOS_FILE_MAX_SIZE_B * 2);
>  #endif
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h
> index a4ec60f6c317..975d12359358 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.h
> @@ -574,7 +574,7 @@ struct amdgpu_psp_funcs {
>         (psp)->funcs->update_spirom((psp), fw_pri_mc_addr) : -EINVAL)
>
>  #define psp_dump_spirom(psp, fw_pri_mc_addr) \
> -       ((psp)->funcs->dump_spirom ? \
> +       (((psp)->funcs && (psp)->funcs->dump_spirom) ? \
>         (psp)->funcs->dump_spirom((psp), fw_pri_mc_addr) : -EINVAL)
>
>  #define psp_vbflash_status(psp) \
>
> base-commit: 83f32c773255720a661aa45d83e36278135f23f5
> --
> 2.56.0
>