From: Dongliang Mu <mudongliangabcd@xxxxxxxxx> [ Upstream commit 07922937e9a580825f9965c46fd15e23ba5754b6 ] hdpvr_register_videodev is responsible to initialize a worker in hdpvr_device. However, the worker is only initialized at hdpvr_start_streaming other than hdpvr_register_videodev. When hdpvr_probe does not initialize its worker, the hdpvr_disconnect will encounter one WARN in flush_work.The stack trace is as follows: hdpvr_disconnect+0xb8/0xf2 drivers/media/usb/hdpvr/hdpvr-core.c:425 usb_unbind_interface+0xbf/0x3a0 drivers/usb/core/driver.c:458 __device_release_driver drivers/base/dd.c:1206 [inline] device_release_driver_internal+0x22a/0x230 drivers/base/dd.c:1237 bus_remove_device+0x108/0x160 drivers/base/bus.c:529 device_del+0x1fe/0x510 drivers/base/core.c:3592 usb_disable_device+0xd1/0x1d0 drivers/usb/core/message.c:1419 usb_disconnect+0x109/0x330 drivers/usb/core/hub.c:2228 Fix this by moving the initialization of dev->worker to the starting of hdpvr_register_videodev Reported-by: syzkaller <syzkaller@xxxxxxxxxxxxxxxx> Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/media/usb/hdpvr/hdpvr-video.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/hdpvr/hdpvr-video.c b/drivers/media/usb/hdpvr/hdpvr-video.c index 0615996572e4..ce46f8721470 100644 --- a/drivers/media/usb/hdpvr/hdpvr-video.c +++ b/drivers/media/usb/hdpvr/hdpvr-video.c @@ -312,7 +312,6 @@ static int hdpvr_start_streaming(struct hdpvr_device *dev) dev->status = STATUS_STREAMING; - INIT_WORK(&dev->worker, hdpvr_transmit_buffers); schedule_work(&dev->worker); v4l2_dbg(MSG_BUFFER, hdpvr_debug, &dev->v4l2_dev, @@ -1175,6 +1174,9 @@ int hdpvr_register_videodev(struct hdpvr_device *dev, struct device *parent, bool ac3 = dev->flags & HDPVR_FLAG_AC3_CAP; int res; + // initialize dev->worker + INIT_WORK(&dev->worker, hdpvr_transmit_buffers); + dev->cur_std = V4L2_STD_525_60; dev->width = 720; dev->height = 480; -- 2.34.1
