This is a note to let you know that I've just added the patch titled media: mtk-jpeg: Fix use after free bug due to uncanceled work to the 6.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: media-mtk-jpeg-fix-use-after-free-bug-due-to-uncance.patch and it can be found in the queue-6.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5f21f63a91c923ce7c4991bb1ca805ca168afe16 Author: Zheng Wang <zyytlz.wz@xxxxxxx> Date: Fri Jul 7 17:24:14 2023 +0800 media: mtk-jpeg: Fix use after free bug due to uncanceled work [ Upstream commit c677d7ae83141d390d1253abebafa49c962afb52 ] 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 <zyytlz.wz@xxxxxxx> Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx> Reviewed-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c index 60425c99a2b8b..7194f88edc0fb 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);