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=-19.1 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, USER_AGENT_GIT autolearn=unavailable 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 71BEBC433EF for ; Thu, 16 Sep 2021 16:11:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 575986127B for ; Thu, 16 Sep 2021 16:11:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234587AbhIPQMp (ORCPT ); Thu, 16 Sep 2021 12:12:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:47626 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233496AbhIPQHo (ORCPT ); Thu, 16 Sep 2021 12:07:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6DF946128A; Thu, 16 Sep 2021 16:06:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631808380; bh=dSirCzk0BY2TPKfpn5m0PiD+vBnmXAxuVQrYuoQ3amg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IvR5rW/yUjqY7NWqrkuxf9Bf4cXfubXRE+57fYdCU0PlFXqu18ouwVSCPK1agD2iV AGCIuT/R43V63ILkMR63omKSsY6tDJBblWAUamP7T5HNH9hskT1H579bPSe4MqriNn s3w7BlLc4pVV09Q8dHlThkV+uaZt860VmwwvJmU4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Laurent Pinchart , Mauro Carvalho Chehab Subject: [PATCH 5.10 037/306] media: uvc: dont do DMA on stack Date: Thu, 16 Sep 2021 17:56:22 +0200 Message-Id: <20210916155755.215626286@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916155753.903069397@linuxfoundation.org> References: <20210916155753.903069397@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mauro Carvalho Chehab commit 1a10d7fdb6d0e235e9d230916244cc2769d3f170 upstream. As warned by smatch: drivers/media/usb/uvc/uvc_v4l2.c:911 uvc_ioctl_g_input() error: doing dma on the stack (&i) drivers/media/usb/uvc/uvc_v4l2.c:943 uvc_ioctl_s_input() error: doing dma on the stack (&i) those two functions call uvc_query_ctrl passing a pointer to a data at the DMA stack. those are used to send URBs via usb_control_msg(). Using DMA stack is not supported and should not work anymore on modern Linux versions. So, use a kmalloc'ed buffer. Cc: stable@vger.kernel.org # Kernel 4.9 and upper Reviewed-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/uvc/uvc_v4l2.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) --- a/drivers/media/usb/uvc/uvc_v4l2.c +++ b/drivers/media/usb/uvc/uvc_v4l2.c @@ -898,8 +898,8 @@ static int uvc_ioctl_g_input(struct file { struct uvc_fh *handle = fh; struct uvc_video_chain *chain = handle->chain; + u8 *buf; int ret; - u8 i; if (chain->selector == NULL || (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) { @@ -907,22 +907,27 @@ static int uvc_ioctl_g_input(struct file return 0; } + buf = kmalloc(1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id, chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL, - &i, 1); - if (ret < 0) - return ret; + buf, 1); + if (!ret) + *input = *buf - 1; - *input = i - 1; - return 0; + kfree(buf); + + return ret; } static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input) { struct uvc_fh *handle = fh; struct uvc_video_chain *chain = handle->chain; + u8 *buf; int ret; - u32 i; ret = uvc_acquire_privileges(handle); if (ret < 0) @@ -938,10 +943,17 @@ static int uvc_ioctl_s_input(struct file if (input >= chain->selector->bNrInPins) return -EINVAL; - i = input + 1; - return uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id, - chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL, - &i, 1); + buf = kmalloc(1, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + *buf = input + 1; + ret = uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id, + chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL, + buf, 1); + kfree(buf); + + return ret; } static int uvc_ioctl_queryctrl(struct file *file, void *fh,