[PATCH 4.4 07/16] media: usbtv: Fix refcounting mixup

From: Greg Kroah-Hartman
Date: Fri Oct 16 2020 - 05:07:31 EST


From: Oliver Neukum <oneukum@xxxxxxxx>

commit bf65f8aabdb37bc1a785884374e919477fe13e10 upstream.

The premature free in the error path is blocked by V4L
refcounting, not USB refcounting. Thanks to
Ben Hutchings for review.

[v2] corrected attributions

Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
Fixes: 50e704453553 ("media: usbtv: prevent double free in error case")
CC: stable@xxxxxxxxxxxxxxx
Reported-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/media/usb/usbtv/usbtv-core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/media/usb/usbtv/usbtv-core.c
+++ b/drivers/media/usb/usbtv/usbtv-core.c
@@ -96,7 +96,8 @@ static int usbtv_probe(struct usb_interf

usbtv_audio_fail:
/* we must not free at this point */
- usb_get_dev(usbtv->udev);
+ v4l2_device_get(&usbtv->v4l2_dev);
+ /* this will undo the v4l2_device_get() */
usbtv_video_free(usbtv);

usbtv_video_fail: