From nobody Sat May 10 05:24:49 2025 Delivered-To: importer2@patchew.org Received-SPF: pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; envelope-from=linux-kernel-owner@vger.kernel.org; helo=vger.kernel.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass(p=none dis=none) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; t=1624281821; cv=none; d=zohomail.com; s=zohoarc; b=bbvZVZoE392ZO5kFWoTT/WnVs/4JhBFuZ27MRNOtewzkiLlpFqMcVgexzT4zjFBZfm7mSbtqYBWUKK70cdUd5cL7+ZNu5NiSkqZAkIzvJaaf3UNaLOdn4AwRIDUy5L0OAIJq3nHWK9XUOguSAggHKBGGgVscJxKTtrKsd+Ywv44= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1624281821; h=Content-Transfer-Encoding:Cc:Date:From:List-Id:MIME-Version:Message-ID:Sender:Subject:To; bh=tzQ2LpYeUc7punAZFQUzAApbkoOscED0f2EJaHr+gWk=; b=D9ziNBFA6K/E1KnA6TavngNAhkg/ydgdZFANlSbkCR7qeq7TDo6xZFQ6hjEm84kL6XnEr+wljNIoALovU0YKBHgvjvKJbmUzv2VwnabTjUMpYFgYStlfBxrnzCQJDbni/lGukcxkQzAE8oLDed4mtR6ssbzaAs+CsbuefNDrg8w= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mx.zohomail.com with SMTP id 162428182179337.06285645396531; Mon, 21 Jun 2021 06:23:41 -0700 (PDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229904AbhFUNZy (ORCPT ); Mon, 21 Jun 2021 09:25:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:50402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229707AbhFUNZx (ORCPT ); Mon, 21 Jun 2021 09:25:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 23777611BD; Mon, 21 Jun 2021 13:23:39 +0000 (UTC) Received: by mail.kernel.org with local (Exim 4.94.2) (envelope-from ) id 1lvJto-000X9q-KM; Mon, 21 Jun 2021 15:23:36 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624281819; bh=WfMt+2CnAOmcD9w6YclfhB+NcpEBJQj+GsdnDBwKwag=; h=From:To:Cc:Subject:Date:From; b=sA+aAXvspoGifjqV4cB9p6smfGXfpcOqcSwaLb8Kr76Hah1/cWGfrMPrT6NcSeMOw uDTY9yztibFcukLUmXeN4lA7Ab7txzhTTPWmEz0okY8QtoKWFYyKwr7Hp8H4L7hQy4 Bkfvl7SJBtCiyjxHsjfBTtKjYJX6Vmf5G7Wi+y1J/+nt/mFxU+ydEsuJSEDXroD5dY e2sHI9C3p9Gei8s94ZKdJ22HiCX+HxGzHVATIa2t7GhlsizPXNLC18nq6IV1YhBVVI PjD/aswMgpyHRCoLuKwpLNbk+CHd5IOD9A8Msfs0RuM9W55dN8Y2iZk5zzs8jYWN3h rMw/Q2xHzpVAg== From: Mauro Carvalho Chehab Cc: linuxarm@huawei.com, mauro.chehab@huawei.com, Mauro Carvalho Chehab , Laurent Pinchart , Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH v2] media: uvc: don't do DMA on stack Date: Mon, 21 Jun 2021 15:23:35 +0200 Message-Id: X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: Mauro Carvalho Chehab To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" 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 temporary buffer, allocated together with struct uvc_video_chain. Cc: stable@vger.kernel.org # Kernel 4.9 and upper Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/uvc/uvc_v4l2.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v= 4l2.c index 252136cc885c..d680ae8a5f87 100644 --- a/drivers/media/usb/uvc/uvc_v4l2.c +++ b/drivers/media/usb/uvc/uvc_v4l2.c @@ -899,8 +899,8 @@ static int uvc_ioctl_g_input(struct file *file, void *f= h, unsigned int *input) { struct uvc_fh *handle =3D fh; struct uvc_video_chain *chain =3D handle->chain; + char *buf; int ret; - u8 i; =20 if (chain->selector =3D=3D NULL || (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) { @@ -908,13 +908,18 @@ static int uvc_ioctl_g_input(struct file *file, void = *fh, unsigned int *input) return 0; } =20 + buf =3D kmalloc(1, GFP_KERNEL); + ret =3D uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id, chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL, - &i, 1); + buf, 1); if (ret < 0) return ret; =20 - *input =3D i - 1; + *input =3D *buf; + + kfree(buf); + return 0; } =20 @@ -922,8 +927,8 @@ static int uvc_ioctl_s_input(struct file *file, void *f= h, unsigned int input) { struct uvc_fh *handle =3D fh; struct uvc_video_chain *chain =3D handle->chain; + char *buf; int ret; - u32 i; =20 ret =3D uvc_acquire_privileges(handle); if (ret < 0) @@ -939,10 +944,15 @@ static int uvc_ioctl_s_input(struct file *file, void = *fh, unsigned int input) if (input >=3D chain->selector->bNrInPins) return -EINVAL; =20 - i =3D 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 =3D kmalloc(1, GFP_KERNEL); + + *buf =3D input + 1; + ret =3D 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; } =20 static int uvc_ioctl_queryctrl(struct file *file, void *fh, --=20 2.31.1