From patchwork Thu Jan 7 14:31:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 358240 Delivered-To: patch@linaro.org Received: by 2002:a02:85a7:0:0:0:0:0 with SMTP id d36csp534424jai; Thu, 7 Jan 2021 06:32:30 -0800 (PST) X-Google-Smtp-Source: ABdhPJzU5OpNxHVdjukeJJ0kFIzPVg7h4yGZwt9j5RkcfrBzJqmORJIES5RZ4DNjwx8K5NRok9uC X-Received: by 2002:a17:906:29c2:: with SMTP id y2mr6745541eje.518.1610029950686; Thu, 07 Jan 2021 06:32:30 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1610029950; cv=none; d=google.com; s=arc-20160816; b=Swf7z8+aLBOINWwHQVzXbV+dvooLJxrfGeJw3xFUJE/Bsu2OR8qQ010V1up0Tj4qOM zdXsKXfmI7ooYav8xn2J1efZdL1/suknlSSvZp+Lih1b1sCNgUVVK3tOPOrQldui0Zu4 3nkwyFuvzppckkl+X0JT5j5SUVCe8E2etwQpSHAwfWy3bXW3aPuU2ps5Oc0Y0EyMaDRQ 0a/ZK6qV0RD3acCmyWbVy/NeBRcRL9Vv9KyTbwcSfm3kuPll8UDQQfVuGFvhkIcuIvXh iyFAa/FzbnmMQOwh/Uk5++fyualFhqAmksOgCB+Ef6pjjY6s5qaqLer1+Guh5oCSijw3 N0iA== 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=pd6N0dYV9Vo/HKOyHagu7Bva4p/fCbP5h7gFkl/6mw4=; b=aLrxNhGFo53Yl9V2GfDtMZaiu7iIkwExQsXKiHhAwePjVcYq5Si3H4p7yYdVumjktT j+CpJn8t0ANCYDOqn2/+qDU03PmmaSgeruOxNzHuCNFtj5LCadcsO1a8Zykim9Xwenhz VotHN3CWeu1yFAt74DIxLR6ZVdTFW+DA+USi/NMAj6QxUD4S9Tjf0e0SsziBytE+x+V3 t67rggqZ2m+83oOwXGfJIX8HTrehicI2ixAiPvN6hvR4tOh1SKfNhkulG++b31ORlX9q nwow3V5tubzswfl7FRZ+Wv0RgcN50c06uf6sznrlV4cXhUzr68L+YazLidr8L4ujcPyq QmaA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=vSPOx5EG; 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 t23si2373287ejs.184.2021.01.07.06.32.30; Thu, 07 Jan 2021 06:32:30 -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=vSPOx5EG; 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 S1729286AbhAGOcS (ORCPT + 14 others); Thu, 7 Jan 2021 09:32:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:46366 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729267AbhAGOcR (ORCPT ); Thu, 7 Jan 2021 09:32:17 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 212F223343; Thu, 7 Jan 2021 14:31:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610029874; bh=RFw+n++0ZHliEK3pgZhexrztSDm+0bCdgrR26y+fNP4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vSPOx5EGvU1jRn0ais+akARktG+HBvckx1CmYJYhAnbC4imfJ6WuuEOSkyRuTQd36 nWU0Hn18TmIqBWUeCQ4K9VCCHIf+j7EEqJnpsqMvhSLxEfX36yZ/HclfoET9I4toin 9QBFyQc5JD0Fi3y0aAEivueSL9stN/axPzzDqtvk= 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 4.14 27/29] iio:imu:bmi160: Fix alignment and data leak issues Date: Thu, 7 Jan 2021 15:31:42 +0100 Message-Id: <20210107143056.819028678@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210107143052.973437064@linuxfoundation.org> References: <20210107143052.973437064@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(sample)); 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);