@@ -358,24 +358,52 @@ int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
{
- return vb2_mmap(&queue->queue, vma);
+ struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+ int ret;
+
+ mutex_lock(&queue->mutex);
+ if (!video_is_registered(&stream->vdev)) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+ ret = vb2_mmap(&queue->queue, vma);
+unlock:
+ mutex_unlock(&queue->mutex);
+ return ret;
}
#ifndef CONFIG_MMU
unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
unsigned long pgoff)
{
- return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+ struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+ unsigned long ret;
+
+ mutex_lock(&queue->mutex);
+ if (!video_is_registered(&stream->vdev)) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+ ret = vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+unlock:
+ mutex_unlock(&queue->mutex);
+ return ret;
}
#endif
__poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
poll_table *wait)
{
+ struct uvc_streaming *stream = uvc_queue_to_stream(queue);
__poll_t ret;
mutex_lock(&queue->mutex);
+ if (!video_is_registered(&stream->vdev)) {
+ ret = EPOLLERR;
+ goto unlock;
+ }
ret = vb2_poll(&queue->queue, file, wait);
+unlock:
mutex_unlock(&queue->mutex);
return ret;
uvc queue file operations have no mutex protection against USB disconnect. This is questionable at least for the poll operation, which has to wait for the uvc queue mutex. By the time that mutex has been acquired, is it possible that the video device has been unregistered. Protect all file operations by using the queue mutex to avoid possible race conditions. After acquiring the mutex, check if the video device is still registered, and bail out if not. Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- v2: Return EPOLLERR instead of -ENODEV on poll errors drivers/media/usb/uvc/uvc_queue.c | 32 +++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)