From 3dbbbc3cafa2de377d9b97af4e35b8b6b5282047 Mon Sep 17 00:00:00 2001 From: Shuangpeng Bai Date: Wed, 12 Aug 2026 23:12:35 -0400 Subject: media: gspca: use vb2_video_unregister_device() on disconnect gspca uses vb2_fop_release(), but gspca_disconnect() only unregisters the video device. If the queue owner closes the device after USB disconnect, vb2_fop_release() releases the queue and invokes gspca_stop_streaming() at that point. gspca_stream_off() calls subdriver stop callbacks and usb_set_interface() through gspca_dev->dev. By the time the late close runs, the USB core can have freed the usb_device, resulting in a use-after-free. This was observed as a KASAN use-after-free in sd_stopN(). Use vb2_video_unregister_device() so the queue is released and streaming is stopped synchronously during disconnect, while the usb_device is still valid. Since the helper takes the queue lock, which is usb_lock, call it after dropping that lock. Fixes: f729ef5796d8 ("media: videobuf2-v4l2.c: add vb2_video_unregister_device helper function") Cc: stable@vger.kernel.org # 5.10.x Suggested-by: Hans Verkuil Signed-off-by: Shuangpeng Bai Signed-off-by: Hans Verkuil --- drivers/media/usb/gspca/gspca.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/media/usb/gspca/gspca.c b/drivers/media/usb/gspca/gspca.c index 594d73e50b9f..4185c9047241 100644 --- a/drivers/media/usb/gspca/gspca.c +++ b/drivers/media/usb/gspca/gspca.c @@ -1636,9 +1636,8 @@ void gspca_disconnect(struct usb_interface *intf) #endif v4l2_device_disconnect(&gspca_dev->v4l2_dev); - video_unregister_device(&gspca_dev->vdev); - mutex_unlock(&gspca_dev->usb_lock); + vb2_video_unregister_device(&gspca_dev->vdev); /* (this will call gspca_release() immediately or on last close) */ v4l2_device_put(&gspca_dev->v4l2_dev); -- cgit v1.2.3