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

Dmitry Osipenko
2022-05-26T23:54:27Z

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