From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53D47C433E6 for ; Tue, 9 Feb 2021 17:55:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BD9C64EC0 for ; Tue, 9 Feb 2021 17:55:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233336AbhBIRv7 (ORCPT ); Tue, 9 Feb 2021 12:51:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:60042 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233365AbhBIRmZ (ORCPT ); Tue, 9 Feb 2021 12:42:25 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id CA35864EC2; Tue, 9 Feb 2021 17:40:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612892447; bh=3FqKB+k3RfOfv2X1i7iR67+j0FQVQ8+RruM8LxXLsvw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=I5AP7v2VNsVgS/qju4gDvVBnYtI9mQXeTQanUHIEvN1JD8Z6OCEDer4t3+NYktWia qtnhM2eX8k7TpH+I67PHgI2LajOWhc/6pVFNlF8LIVslIlts8/OEbLZKRn+0lfxIVX yPGHtMQNeLxJ0m493QUx4/0sNXij4z+e9ME1AgOk= Date: Tue, 9 Feb 2021 18:40:44 +0100 From: Greg KH To: ameynarkhede03@gmail.com Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] staging: gdm724x: Fix DMA from stack Message-ID: References: <20210209145415.29609-1-ameynarkhede03@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210209145415.29609-1-ameynarkhede03@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 09, 2021 at 08:24:15PM +0530, ameynarkhede03@gmail.com wrote: > From: Amey Narkhede > > Stack allocated buffers cannot be used for DMA > on all architectures so allocate usbdev buffer > using kmalloc(). > > Signed-off-by: Amey Narkhede > --- > drivers/staging/gdm724x/gdm_usb.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c > index dc4da66c3..50dc463d4 100644 > --- a/drivers/staging/gdm724x/gdm_usb.c > +++ b/drivers/staging/gdm724x/gdm_usb.c > @@ -56,7 +56,7 @@ static int gdm_usb_recv(void *priv_dev, > > static int request_mac_address(struct lte_udev *udev) > { > - u8 buf[16] = {0,}; > + u8 *buf; > struct hci_packet *hci = (struct hci_packet *)buf; > struct usb_device *usbdev = udev->usbdev; > int actual; > @@ -66,6 +66,10 @@ static int request_mac_address(struct lte_udev *udev) > hci->len = gdm_cpu_to_dev16(udev->gdm_ed, 1); > hci->data[0] = MAC_ADDRESS; > > + buf = kmalloc(16, GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + This is great, but you just added a build warning, which implies that the patch is incorrect. You also have a memory leak here, which is not acceptable :( thanks, greg k-h