From: Fabian Vogt <fabian@ritter-vogt.de> [ Upstream commit 3e7c2510bdfe89a9ec223dd7acd6bfc8bb1cbeb6 ] Before this, it wrote as much as available into the buffer, even if it didn't fit. Fixes: b84a8dee23fd ("usb: gadget: add Faraday fotg210_udc driver") Signed-off-by: Fabian Vogt <fabian@ritter-vogt.de> Link: https://lore.kernel.org/r/20210324141115.9384-7-fabian@ritter-vogt.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/usb/gadget/udc/fotg210-udc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/udc/fotg210-udc.c b/drivers/usb/gadget/udc/fotg210-udc.c index 41cc5babd50d9..7ae0243c32e59 100644 --- a/drivers/usb/gadget/udc/fotg210-udc.c +++ b/drivers/usb/gadget/udc/fotg210-udc.c @@ -337,8 +337,9 @@ static void fotg210_start_dma(struct fotg210_ep *ep, } else { buffer = req->req.buf + req->req.actual; length = ioread32(ep->fotg210->reg + - FOTG210_FIBCR(ep->epnum - 1)); - length &= FIBCR_BCFX; + FOTG210_FIBCR(ep->epnum - 1)) & FIBCR_BCFX; + if (length > req->req.length - req->req.actual) + length = req->req.length - req->req.actual; } } else { buffer = req->req.buf + req->req.actual; -- 2.25.1