Messages in this thread Patch in this message | | | From | Zheng Wang <> | Subject | [RESEND PATCH] media: mtk-jpeg: Fix use after free bug due to uncanceled work | Date | Mon, 6 Mar 2023 14:26:33 +0800 |
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In mtk_jpeg_probe, &jpeg->job_timeout_work is bound with mtk_jpeg_job_timeout_work. Then mtk_jpeg_dec_device_run and mtk_jpeg_enc_device_run may be called to start the work. If we remove the module which will call mtk_jpeg_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 the mtk_jpeg_remove
CPU0 CPU1
|mtk_jpeg_job_timeout_work mtk_jpeg_remove | 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/media/platform/mediatek/jpeg/mtk_jpeg_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c index 969516a940ba..364513e7897e 100644 --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c @@ -1793,7 +1793,7 @@ static int mtk_jpeg_probe(struct platform_device *pdev) static int mtk_jpeg_remove(struct platform_device *pdev) { struct mtk_jpeg_dev *jpeg = platform_get_drvdata(pdev); - + cancel_delayed_work(&jpeg->job_timeout_work); pm_runtime_disable(&pdev->dev); video_unregister_device(jpeg->vdev); v4l2_m2m_release(jpeg->m2m_dev); -- 2.25.1
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