Re: [PATCH v6 04/22] drm/panfrost: Fix shrinker list corruption by madvise IOCTL

Alyssa Rosenzweig
2022-05-27T15:57:47Z

Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>

On Fri, May 27, 2022 at 02:50:22AM +0300, Dmitry Osipenko wrote:
> Calling madvise IOCTL twice on BO causes memory shrinker list corruption
> and crashes kernel because BO is already on the list and it's added to
> the list again, while BO should be removed from from the list before it's
> re-added. Fix it.
>
> Cc: stable@vger.kernel.org
> Fixes: 013b65101315 ("drm/panfrost: Add madvise and shrinker support")
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> ---
> drivers/gpu/drm/panfrost/panfrost_drv.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 087e69b98d06..b1e6d238674f 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -433,8 +433,8 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
>
> if (args->retained) {
> if (args->madv == PANFROST_MADV_DONTNEED)
> - list_add_tail(&bo->base.madv_list,
> - &pfdev->shrinker_list);
> + list_move_tail(&bo->base.madv_list,
> + &pfdev->shrinker_list);
> else if (args->madv == PANFROST_MADV_WILLNEED)
> list_del_init(&bo->base.madv_list);
> }
> --
> 2.35.3
>