media: cedrus: fix use after free bug in cedrus_remove due to race condition

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[ Upstream commit 50d0a7aea4 ]

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: 7c38a551bd ("media: cedrus: Add watchdog for job completion")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

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Zheng Wang 2023-03-13 16:31:20 +00:00 • committed by Greg Kroah-Hartman

parent 231a6947ff

commit 2cdc8f729d

1 changed files with 1 additions and 0 deletions

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drivers/staging/media/sunxi/cedrus/cedrus.c

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