This is a note to let you know that I've just added the patch titled
media: cedrus: fix use after free bug in cedrus_remove due to race condition
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-cedrus-fix-use-after-free-bug-in-cedrus_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 0448f6c3462150cfc1533662c2c8f4ad0769da28
Author: Zheng Wang <zyytlz.wz@xxxxxxx>
Date: Mon Mar 13 16:31:20 2023 +0000
media: cedrus: fix use after free bug in cedrus_remove due to race condition
[ Upstream commit 50d0a7aea4809cef87979d4669911276aa23b71f ]
In cedrus_probe, dev->watchdog_work is bound with cedrus_watchdog function.
In cedrus_device_run, it will started by schedule_delayed_work. If there is
an unfinished work in cedrus_remove, there may be a race condition and
trigger UAF bug.
CPU0 CPU1
|cedrus_watchdog
cedrus_remove |
v4l2_m2m_release |
kfree(m2m_dev) |
|
| v4l2_m2m_get_curr_priv
| m2m_dev //use
Fix it by canceling the worker in cedrus_remove.
Fixes: 7c38a551bda1 ("media: cedrus: Add watchdog for job completion")
Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
Acked-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
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/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c
index a43d5ff667163..a50a4d0a8f715 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
@@ -547,6 +547,7 @@ static int cedrus_remove(struct platform_device *pdev)
{
struct cedrus_dev *dev = platform_get_drvdata(pdev);
+ cancel_delayed_work_sync(&dev->watchdog_work);
if (media_devnode_is_registered(dev->mdev.devnode)) {
media_device_unregister(&dev->mdev);
v4l2_m2m_unregister_media_controller(dev->m2m_dev);
