[PATCH 5.10 019/112] drm/panfrost: Fix shrinker list corruption by madvise IOCTL

Greg Kroah-Hartman
2022-07-19T12:21:17Z

From: Dmitry Osipenko <dmitry.osipenko@collabora.com>

commit 9fc33eaaa979d112d10fea729edcd2a2e21aa912 upstream.

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 the list before it's
re-added. Fix it.

Cc: stable@vger.kernel.org
Fixes: 013b65101315 ("drm/panfrost: Add madvise and shrinker support")
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220630200601.1884120-3-dmitry.osipenko@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/panfrost/panfrost_drv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -427,8 +427,8 @@ static int panfrost_ioctl_madvise(struct

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);
}