Hi Dan,
Thank you for the patch.
On Wed, Jun 15, 2022 at 10:09:15PM -0500, Dan Vacura wrote:
> A panic can occur if the endpoint becomes disabled and the
> uvcg_video_pump adds the request back to the req_free list after it has
> already been queued to the endpoint. The endpoint complete will add the
> request back to the req_free list. Invalidate the local request handle
> once it's been queued.
Good catch !
> <6>[ 246.796704][T13726] configfs-gadget gadget: uvc: uvc_function_set_alt(1, 0)
> <3>[ 246.797078][ T26] list_add double add: new=ffffff878bee5c40, prev=ffffff878bee5c40, next=ffffff878b0f0a90.
> <6>[ 246.797213][ T26] ------------[ cut here ]------------
> <2>[ 246.797224][ T26] kernel BUG at lib/list_debug.c:31!
> <6>[ 246.807073][ T26] Call trace:
> <6>[ 246.807180][ T26] uvcg_video_pump+0x364/0x38c
> <6>[ 246.807366][ T26] process_one_work+0x2a4/0x544
> <6>[ 246.807394][ T26] worker_thread+0x350/0x784
> <6>[ 246.807442][ T26] kthread+0x2ac/0x320
>
> Fixes: f9897ec0f6d3 ("usb: gadget: uvc: only pump video data if necessary")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Dan Vacura <w36195@xxxxxxxxxxxx>
> ---
> drivers/usb/gadget/function/uvc_video.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
> index 93f42c7f800d..59e2f51b53a5 100644
> --- a/drivers/usb/gadget/function/uvc_video.c
> +++ b/drivers/usb/gadget/function/uvc_video.c
> @@ -427,6 +427,9 @@ static void uvcg_video_pump(struct work_struct *work)
> if (ret < 0) {
> uvcg_queue_cancel(queue, 0);
> break;
> + } else {
> + /* Endpoint now owns the request */
> + req = NULL;
> }
> video->req_int_count++;
I'd write it as
if (ret < 0) {
uvcg_queue_cancel(queue, 0);
break;
}
/* Endpoint now owns the request. */
req = NULL;
video->req_int_count++;
Apart from that,
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> }
--
Regards,
Laurent Pinchart
