On Fri, May 21, 2021 at 10:16:23PM -0400, Alan Stern wrote:
> When a control URB is submitted, the direction indicated by URB's pipe
> member is supposed to match the direction indicated by the setup
> packet's bRequestType member. A mismatch could lead to trouble,
> depending on which field the host controller drivers use for
> determining the actual direction.
>
> This shouldn't ever happen; it would represent a careless bug in a
> kernel driver somewhere. This patch adds a dev_WARN_ONCE to let
> people know about the potential problem.
>
> Suggested-by: "Geoffrey D. Bennett" <g@xxxxx>
> Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> ---
>
> v2: Use dev_WARN_ONCE instead of dev_WARN
Reviewed-by: Johan Hovold <johan@xxxxxxxxxx>
> drivers/usb/core/urb.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> Index: usb-devel/drivers/usb/core/urb.c
> ===================================================================
> --- usb-devel.orig/drivers/usb/core/urb.c
> +++ usb-devel/drivers/usb/core/urb.c
> @@ -407,6 +407,9 @@ int usb_submit_urb(struct urb *urb, gfp_
> return -ENOEXEC;
> is_out = !(setup->bRequestType & USB_DIR_IN) ||
> !setup->wLength;
> + dev_WARN_ONCE(&dev->dev, (usb_pipeout(urb->pipe) != is_out),
> + "BOGUS control dir, pipe %x doesn't match bRequestType %x\n",
> + urb->pipe, setup->bRequestType);
> } else {
> is_out = usb_endpoint_dir_out(&ep->desc);
> }
Johan
