From patchwork Thu Jan 7 14:32:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 358244 Delivered-To: patch@linaro.org Received: by 2002:a02:85a7:0:0:0:0:0 with SMTP id d36csp538684jai; Thu, 7 Jan 2021 06:37:49 -0800 (PST) X-Google-Smtp-Source: ABdhPJw8ipDTJfHnioZ94sY9aPsGzxQ85Gd1L9OdMRSy0Nq6WHbbFKRR4V7JIvxd+HHHRdf1+yvC X-Received: by 2002:aa7:cd06:: with SMTP id b6mr1905019edw.43.1610030269579; Thu, 07 Jan 2021 06:37:49 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1610030269; cv=none; d=google.com; s=arc-20160816; b=W9fdW/FkZg2jX/eYAPzdq2xAKLgC4QJrDdvksLmC2oGhDLwjzK3rJct28vGk8sZfF5 oNLbzSQQRjkUe7puepomxucRw2fttvEQqZq0VBeVJLLEv0w5DhpAX4fcHAARBYyaJGla 5Oe3HBAH+zq3IEI8y8Dy7sHk0gU5rYBJVMRmwJtlmAQl5GyOjokU3+2weQIJ+UBleUHe tEBQb5WOswOst+BDYJnGNAaqLdzGEg0yhFzbEKenzMNpD7/yy/Ez33Vq9A1k1m91eS/F o9zff/q7lf0UVMwdmK0HC+OJ+pk2Vyg8SuiHiJpR0TgqkN6kRTcEkKinTeUyq56ecwZd h6Eg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=31Xf6FG0zHlnk5nqNOc7d6PYM03s0iGdUQJRSgB0378=; b=iqqM8tyfwXexO7SlYbSoGzrSjSk/S4byYvLDpuQRCvD4D1siKHyBVLz2TotWbmil/y /9st62BoMSMZI7OHFvLDRvY+7AKBJufdEWnlojID6zgZVOrz0VSjdgfeOy0x5/bkaTBK +dT8BVnJaQeil8l7c/WmivBOaqyS3gRp7B3tetfL8kflRkeZx25uagxkMsNcmoe4T2nX 4UbKzGdGpkfcXztwJCX9ZmBfM+yAHw6Y5M034QQWVJWca8UFs5z5rBjPil0VF+10T1c7 /N9prMDedzN07nxdmI4A/fTETLtdf2FrEVIbB/XhyGoH3xPvRmWN922oWJRxzZ1+dZLN Bk1g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=Y5YQcor0; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id a11si2195544eje.119.2021.01.07.06.37.49; Thu, 07 Jan 2021 06:37:49 -0800 (PST) Received-SPF: pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=Y5YQcor0; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729245AbhAGOcM (ORCPT + 14 others); Thu, 7 Jan 2021 09:32:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:45976 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729236AbhAGOcL (ORCPT ); Thu, 7 Jan 2021 09:32:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 46F5D23380; Thu, 7 Jan 2021 14:31:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610029911; bh=NXiBODZDOGHHsvjogMI2/69pXg+hQavbaRF2tkC24qE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y5YQcor0YL9REdcGWmiFjupDNQMHxW8BqaZ+EDKPQejbl2mdIbsL7gZqKqXvsv7PY AFNaetW+2gpcbUnEjW9yQg4NE8YnnGfTF+Id1exhc0yCkO/cNc+SyRkyA8bmWIV3iV rRoA3RRsvvtvJ2LOkr4tfdFzB/kmcahLt3AI47fU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Alexandru Ardelean , Stable@vger.kernel.org, Sudip Mukherjee Subject: [PATCH 4.19 7/8] iio:magnetometer:mag3110: Fix alignment and data leak issues. Date: Thu, 7 Jan 2021 15:32:07 +0100 Message-Id: <20210107143048.590038459@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210107143047.586006010@linuxfoundation.org> References: <20210107143047.586006010@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jonathan Cameron commit 89deb1334252ea4a8491d47654811e28b0790364 upstream One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp() assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses an array of smaller elements on the stack. As Lars also noted this anti pattern can involve a leak of data to userspace and that indeed can happen here. We close both issues by moving to a suitable structure in the iio_priv() data. This data is allocated with kzalloc() so no data can leak apart from previous readings. The explicit alignment of ts is not necessary in this case but does make the code slightly less fragile so I have included it. Fixes: 39631b5f9584 ("iio: Add Freescale mag3110 magnetometer driver") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Alexandru Ardelean Cc: Link: https://lore.kernel.org/r/20200920112742.170751-4-jic23@kernel.org [sudip: adjust context] Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman --- drivers/iio/magnetometer/mag3110.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/iio/magnetometer/mag3110.c +++ b/drivers/iio/magnetometer/mag3110.c @@ -56,6 +56,12 @@ struct mag3110_data { struct mutex lock; u8 ctrl_reg1; int sleep_val; + /* Ensure natural alignment of timestamp */ + struct { + __be16 channels[3]; + u8 temperature; + s64 ts __aligned(8); + } scan; }; static int mag3110_request(struct mag3110_data *data) @@ -387,10 +393,9 @@ static irqreturn_t mag3110_trigger_handl struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct mag3110_data *data = iio_priv(indio_dev); - u8 buffer[16]; /* 3 16-bit channels + 1 byte temp + padding + ts */ int ret; - ret = mag3110_read(data, (__be16 *) buffer); + ret = mag3110_read(data, data->scan.channels); if (ret < 0) goto done; @@ -399,10 +404,10 @@ static irqreturn_t mag3110_trigger_handl MAG3110_DIE_TEMP); if (ret < 0) goto done; - buffer[6] = ret; + data->scan.temperature = ret; } - iio_push_to_buffers_with_timestamp(indio_dev, buffer, + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, iio_get_time_ns(indio_dev)); done: