From c677d7ae83141d390d1253abebafa49c962afb52 Mon Sep 17 00:00:00 2001 From: Zheng Wang Date: Fri, 7 Jul 2023 17:24:14 +0800 Subject: [PATCH] media: mtk-jpeg: Fix use after free bug due to uncanceled work 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 Fixes: b2f0d2724ba4 ("[media] vcodec: mediatek: Add Mediatek JPEG Decoder Driver") Signed-off-by: Zheng Wang Reviewed-by: Alexandre Mergnat Reviewed-by: Chen-Yu Tsai Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Hans Verkuil --- drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c index 40cb3cb..621038a 100644 --- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c +++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c @@ -1403,6 +1403,7 @@ static void mtk_jpeg_remove(struct platform_device *pdev) { struct mtk_jpeg_dev *jpeg = platform_get_drvdata(pdev); + cancel_delayed_work_sync(&jpeg->job_timeout_work); pm_runtime_disable(&pdev->dev); video_unregister_device(jpeg->vdev); v4l2_m2m_release(jpeg->m2m_dev); -- 2.7.4