This is a security bug that has been reported to google.
It affected all platforms on chrome-os. Please apply this
patch to 4.14 4.19 5.4 5.10 and 5.15.
[ 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>
---
- v2: use cancel_delayed_work_sync instead of cancel_delayed_work suggested by Kyrie.
---
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 0051f372a66c..6069ecf420b0 100644
--- a/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
+++ b/drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c
@@ -1816,6 +1816,7 @@ 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);
--
2.25.1
