This is a note to let you know that I've just added the patch titled
media: imx: Fix csc/scaler unregister
to the 5.4-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-imx-fix-csc-scaler-unregister.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4778292a6488fe10f8f5ab975d487241d34e15f4
Author: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
Date: Mon Jan 4 21:34:40 2021 +0100
media: imx: Fix csc/scaler unregister
[ Upstream commit 89b14485caa4b7b2eaf70be0064f0978e68ebeee ]
The csc/scaler device private struct is released by
ipu_csc_scaler_video_device_release(), which can be called
by video_unregister_device() if there are no users
of the underlying struct video device.
Therefore, the mutex can't be held when calling
video_unregister_device() as its memory may be freed
by it, leading to a kernel oops.
Fortunately, the fix is quite simple as no locking
is needed when calling video_unregister_device(): v4l2-core
already has its own internal locking, and the structures
are also properly refcounted.
Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device")
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/staging/media/imx/imx-media-csc-scaler.c b/drivers/staging/media/imx/imx-media-csc-scaler.c
index 2b635ebf62d6a..a15d970adb983 100644
--- a/drivers/staging/media/imx/imx-media-csc-scaler.c
+++ b/drivers/staging/media/imx/imx-media-csc-scaler.c
@@ -866,11 +866,7 @@ void imx_media_csc_scaler_device_unregister(struct imx_media_video_dev *vdev)
struct ipu_csc_scaler_priv *priv = vdev_to_priv(vdev);
struct video_device *vfd = priv->vdev.vfd;
- mutex_lock(&priv->mutex);
-
video_unregister_device(vfd);
-
- mutex_unlock(&priv->mutex);
}
struct imx_media_video_dev *
