media: uvcvideo: Fix error path in control parsing failure

When parsing the UVC control descriptors fails, the error path tries to
cleanup a media device that hasn't been initialised, potentially
resulting in a crash. Fix this by initialising the media device before
the error handling path can be reached.

Fixes: 5a254d751e ("[media] uvcvideo: Register a v4l2_device")
Reported-by: syzbot+c86454eb3af9e8a4da20@syzkaller.appspotmail.com
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Laurent Pinchart 2019-07-29 23:14:55 -03:00 committed by Mauro Carvalho Chehab
parent d9aeaa6d4c
commit 8c279e9394

View File

@ -2151,6 +2151,20 @@ static int uvc_probe(struct usb_interface *intf,
sizeof(dev->name) - len);
}
/* Initialize the media device. */
#ifdef CONFIG_MEDIA_CONTROLLER
dev->mdev.dev = &intf->dev;
strscpy(dev->mdev.model, dev->name, sizeof(dev->mdev.model));
if (udev->serial)
strscpy(dev->mdev.serial, udev->serial,
sizeof(dev->mdev.serial));
usb_make_path(udev, dev->mdev.bus_info, sizeof(dev->mdev.bus_info));
dev->mdev.hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
media_device_init(&dev->mdev);
dev->vdev.mdev = &dev->mdev;
#endif
/* Parse the Video Class control descriptor. */
if (uvc_parse_control(dev) < 0) {
uvc_trace(UVC_TRACE_PROBE, "Unable to parse UVC "
@ -2171,19 +2185,7 @@ static int uvc_probe(struct usb_interface *intf,
"linux-uvc-devel mailing list.\n");
}
/* Initialize the media device and register the V4L2 device. */
#ifdef CONFIG_MEDIA_CONTROLLER
dev->mdev.dev = &intf->dev;
strscpy(dev->mdev.model, dev->name, sizeof(dev->mdev.model));
if (udev->serial)
strscpy(dev->mdev.serial, udev->serial,
sizeof(dev->mdev.serial));
usb_make_path(udev, dev->mdev.bus_info, sizeof(dev->mdev.bus_info));
dev->mdev.hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
media_device_init(&dev->mdev);
dev->vdev.mdev = &dev->mdev;
#endif
/* Register the V4L2 device. */
if (v4l2_device_register(&intf->dev, &dev->vdev) < 0)
goto error;