This is a note to let you know that I've just added the patch titled
media: rkvdec: fix use after free bug in rkvdec_remove
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-rkvdec-fix-use-after-free-bug-in-rkvdec_remove.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cbffaeb2da854ad0102b0dcb942d9d80e514f690
Author: Zheng Wang <zyytlz.wz@xxxxxxx>
Date: Mon Mar 13 16:42:20 2023 +0000
media: rkvdec: fix use after free bug in rkvdec_remove
[ Upstream commit 3228cec23b8b29215e18090c6ba635840190993d ]
In rkvdec_probe, rkvdec->watchdog_work is bound with
rkvdec_watchdog_func. Then rkvdec_vp9_run may
be called to start the work.
If we remove the module which will call rkvdec_remove
to make cleanup, there may be a unfinished work.
The possible sequence is as follows, which will
cause a typical UAF bug.
Fix it by canceling the work before cleanup in rkvdec_remove.
CPU0 CPU1
|rkvdec_watchdog_func
rkvdec_remove |
rkvdec_v4l2_cleanup|
v4l2_m2m_release |
kfree(m2m_dev); |
|
| v4l2_m2m_get_curr_priv
| m2m_dev->curr_ctx //use
Fixes: cd33c830448b ("media: rkvdec: Add the rkvdec driver")
Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c
index 7bab7586918c1..82806f198074a 100644
--- a/drivers/staging/media/rkvdec/rkvdec.c
+++ b/drivers/staging/media/rkvdec/rkvdec.c
@@ -1066,6 +1066,8 @@ static int rkvdec_remove(struct platform_device *pdev)
{
struct rkvdec_dev *rkvdec = platform_get_drvdata(pdev);
+ cancel_delayed_work_sync(&rkvdec->watchdog_work);
+
rkvdec_v4l2_cleanup(rkvdec);
pm_runtime_disable(&pdev->dev);
pm_runtime_dont_use_autosuspend(&pdev->dev);
