| Message ID | 20230307173900.1299387-1-zyytlz.wz@163.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | media: rkvdec: fix use after free bug in rkvdec_remove | expand |
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);
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(+)