| Message ID | 20210524110920.24599-2-johan@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | media: fix zero-length USB control requests | expand |
diff --git a/drivers/media/usb/gspca/gl860/gl860.c b/drivers/media/usb/gspca/gl860/gl860.c index 2c05ea2598e7..ce4ee8bc75c8 100644 --- a/drivers/media/usb/gspca/gl860/gl860.c +++ b/drivers/media/usb/gspca/gl860/gl860.c @@ -561,8 +561,8 @@ int gl860_RTx(struct gspca_dev *gspca_dev, len, 400 + 200 * (len > 1)); memcpy(pdata, gspca_dev->usb_buf, len); } else { - r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), - req, pref, val, index, NULL, len, 400); + gspca_err(gspca_dev, "zero-length read request\n"); + r = -EINVAL; } }
The direction of the pipe argument must match the request-type direction bit or control requests may fail depending on the host-controller-driver implementation. Control transfers without a data stage are treated as OUT requests by the USB stack and should be using usb_sndctrlpipe(). Failing to do so will now trigger a warning. Fix the gl860_RTx() helper so that zero-length control reads fail with an error message instead. Note that there are no current callers that would trigger this. Fixes: 4f7cb8837cec ("V4L/DVB (12954): gspca - gl860: Addition of GL860 based webcams") Signed-off-by: Johan Hovold <johan@kernel.org> --- drivers/media/usb/gspca/gl860/gl860.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)