From patchwork Thu Jan 7 14:16:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 358236 Delivered-To: patch@linaro.org Received: by 2002:a17:906:4755:0:0:0:0 with SMTP id j21csp335602ejs; Thu, 7 Jan 2021 06:18:01 -0800 (PST) X-Google-Smtp-Source: ABdhPJyoj4ec2iEkSwhLZS076VavfXHqGOeqxJKTrzcT+jLV+/1u6Q5vpOoiW1Y3vbpR7oMdVMeU X-Received: by 2002:a17:906:c1d9:: with SMTP id bw25mr6305549ejb.452.1610029080936; Thu, 07 Jan 2021 06:18:00 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1610029080; cv=none; d=google.com; s=arc-20160816; b=zBKigoAakYCnROhu5rcqk3/i6jr5dikfsB0XNrR0kfNaLRhIPmrr8gzakD2eUoud8x kUIJVS2C7fzxH7tcsKLtr0I8srMV9D91eLqRjf+Yctvo48eJAFYFx0KH2BllYsksG93h LeYN1lDhcK6xbqtm99BmNwjnDOpVK932FKCxC3mAS/U9NDYmBNta8GIBWhI8adc0BJmQ QSkiKX410Q97uk6sKR4kJBygy2BcpqJNedaNczLqxwDw2dFOiO42epQkpC8xHL+YRJot HNBWrBm/cAVtHpTNXUO3rld+CxfTFk7xStGzOa7RdsoG0zWg7JokCGI+ylGQcKWPM1+3 kWGg== 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=zSxrHxQ2WCMkzPWB8yj5naRNCU7WxH8VD5d/0LChfvw=; b=vlepX6UvdepDeqe8CSHWZm0CTo7hIBUjxE81pA2LHZRPiSbyu/gTQD9gi6FYCb0Apd jIse649exfWubRGVc0CTGTEx5k0x4esO2v2dHA/wzpOBllD4OrdTi95SLDa4lZv1zoXD KsZW6uBfhw+VxfRyUrRkdA5/r9i9GF1hKXk6rqcyyxNJnk5zKtZ1OLLdniCUa6t1+XSG ykoIFLobPgL33mBA8gjxZUMn53RgmxNH/K7f/oUc7DhKCb1UQ8VUs+AuhPUP1tW6OzCU aqUJHi/Q2LSGB7L07FGWMWRRSH4LLZkOP45H8RwNzKpFxUlGnYJhP42ljOkRld6yqVOz E1QA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=N7lIhIZ3; 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 y1si2241480eds.331.2021.01.07.06.18.00; Thu, 07 Jan 2021 06:18:00 -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=N7lIhIZ3; 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 S1729238AbhAGOR4 (ORCPT + 14 others); Thu, 7 Jan 2021 09:17:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:39548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729226AbhAGORm (ORCPT ); Thu, 7 Jan 2021 09:17:42 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id BDD722339D; Thu, 7 Jan 2021 14:17:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610029039; bh=TMq98OZqmHcdfl9t1L0ZCgxJfqgUJ3u+SDr2y5fFVjc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N7lIhIZ32IBOursUbRyYL958rgWGgCX3E+630BtqzZ0Hijm6OLOp5EuDH2kGlk5/Z RwB4Rt7FejWi97UymSYNWAjIv0uMt/dACVxbOLqzBkpFwM4Jw2IXDDk0AS1a8GErAq IdxPMYlIGn4eohQ6z8TIMfRpbt6dicACfvdasGa4= 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 , Daniel Baluta , Daniel Baluta , Stable@vger.kernel.org, Sudip Mukherjee Subject: [PATCH 4.9 31/32] iio:imu:bmi160: Fix alignment and data leak issues Date: Thu, 7 Jan 2021 15:16:51 +0100 Message-Id: <20210107140829.344820506@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210107140827.866214702@linuxfoundation.org> References: <20210107140827.866214702@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 7b6b51234df6cd8b04fe736b0b89c25612d896b8 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 array in the iio_priv() data with alignment explicitly requested. This data is allocated with kzalloc() so no data can leak apart from previous readings. In this driver, depending on which channels are enabled, the timestamp can be in a number of locations. Hence we cannot use a structure to specify the data layout without it being misleading. Fixes: 77c4ad2d6a9b ("iio: imu: Add initial support for Bosch BMI160") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Alexandru Ardelean Cc: Daniel Baluta Cc: Daniel Baluta Cc: Link: https://lore.kernel.org/r/20200920112742.170751-6-jic23@kernel.org [sudip: adjust context and use bmi160_data in old location] Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman --- drivers/iio/imu/bmi160/bmi160_core.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/iio/imu/bmi160/bmi160_core.c +++ b/drivers/iio/imu/bmi160/bmi160_core.c @@ -110,6 +110,13 @@ enum bmi160_sensor_type { struct bmi160_data { struct regmap *regmap; + /* + * Ensure natural alignment for timestamp if present. + * Max length needed: 2 * 3 channels + 4 bytes padding + 8 byte ts. + * If fewer channels are enabled, less space may be needed, as + * long as the timestamp is still aligned to 8 bytes. + */ + __le16 buf[12] __aligned(8); }; const struct regmap_config bmi160_regmap_config = { @@ -385,8 +392,6 @@ static irqreturn_t bmi160_trigger_handle struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct bmi160_data *data = iio_priv(indio_dev); - __le16 buf[12]; - /* 2 sens x 3 axis x __le16 + 2 x __le16 pad + 4 x __le16 tstamp */ int i, ret, j = 0, base = BMI160_REG_DATA_MAGN_XOUT_L; __le16 sample; @@ -396,10 +401,10 @@ static irqreturn_t bmi160_trigger_handle &sample, sizeof(__le16)); if (ret < 0) goto done; - buf[j++] = sample; + data->buf[j++] = sample; } - iio_push_to_buffers_with_timestamp(indio_dev, buf, + iio_push_to_buffers_with_timestamp(indio_dev, data->buf, iio_get_time_ns(indio_dev)); done: iio_trigger_notify_done(indio_dev->trig);