Messages in this thread Patch in this message | | | From | Zheng Wang <> | Subject | [PATCH] media: rkvdec: fix use after free bug in rkvdec_remove | Date | Wed, 8 Mar 2023 01:39:00 +0800 |
| |
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
Signed-off-by: Zheng Wang <zyytlz.wz@163.com> --- drivers/staging/media/rkvdec/rkvdec.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c index 7bab7586918c..6b14655a8e2c 100644 --- a/drivers/staging/media/rkvdec/rkvdec.c +++ b/drivers/staging/media/rkvdec/rkvdec.c @@ -1066,6 +1066,7 @@ static int rkvdec_remove(struct platform_device *pdev) { struct rkvdec_dev *rkvdec = platform_get_drvdata(pdev); + cancel_delayed_work(&rkvdec->watchdog_work); rkvdec_v4l2_cleanup(rkvdec); pm_runtime_disable(&pdev->dev); pm_runtime_dont_use_autosuspend(&pdev->dev); -- 2.25.1
| |