urb allocation will fail when usbtest_alloc_urb() tries to allocate zero length buffer, but it doesn't need it in fact, so just skips buffer allocation in the case. Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> --- drivers/usb/misc/usbtest.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c index 92fdb6e..de485d8 100644 --- a/drivers/usb/misc/usbtest.c +++ b/drivers/usb/misc/usbtest.c @@ -287,6 +287,9 @@ static struct urb *usbtest_alloc_urb( if (usb_pipein(pipe)) urb->transfer_flags |= URB_SHORT_NOT_OK; + if ((bytes + offset) == 0) + return urb; + if (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) urb->transfer_buffer = usb_alloc_coherent(udev, bytes + offset, GFP_KERNEL, &urb->transfer_dma); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html