From patchwork Sun Jun 7 15:53:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 11591695 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8F4B9913 for ; Sun, 7 Jun 2020 15:56:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 793C72076A for ; Sun, 7 Jun 2020 15:56:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591545400; bh=phINfUjXz2CIGUvz/IAoTkNjUthzAtgr7B+EcO0G7ms=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KU/8wEnzdFu1EVdqO7X/9/TH9RIRkY9MqDXonGSazzqGJ0GUFnSTYYePr5bGw1pnq dZkDh2bvNIywofsR4jg/bP+VeP7WYgacjU6dP/QgZVIBuauBvB1L5Gayen+JTjc9wu S19kA0EbW5zfxVl0PgApAXQCdRoCFXYXKgJOSvI8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726742AbgFGP4j (ORCPT ); Sun, 7 Jun 2020 11:56:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:57500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726703AbgFGP4j (ORCPT ); Sun, 7 Jun 2020 11:56:39 -0400 Received: from localhost.localdomain (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1CC1C20774; Sun, 7 Jun 2020 15:56:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591545399; bh=phINfUjXz2CIGUvz/IAoTkNjUthzAtgr7B+EcO0G7ms=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YUk7n+QvBjZZ5mI2Btyzt0yDKsnnERsxb50aaewEJdZVx2xFr4sLvVtk7PFdWnMet 1Mk3xh8bUCsz2fhH5gwU+jQeUT1Benwpw8yAdPFsP5aU4P8msVm+BaMJM7TGQ95QLM IJzgZ6obFfdW6DmVP8hWy+0VYVUHFEa0KFbHGCLU= From: Jonathan Cameron To: linux-iio@vger.kernel.org Cc: Andy Shevchenko , Jonathan Cameron , Lars-Peter Clausen , Daniel Baluta Subject: [PATCH 18/32] iio:imu:bmi160 Fix alignment and data leak issues Date: Sun, 7 Jun 2020 16:53:54 +0100 Message-Id: <20200607155408.958437-19-jic23@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200607155408.958437-1-jic23@kernel.org> References: <20200607155408.958437-1-jic23@kernel.org> MIME-Version: 1.0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Jonathan Cameron 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. Fixes: 77c4ad2d6a9b ("iio: imu: Add initial support for Bosch BMI160") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Cc: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/imu/bmi160/bmi160.h | 2 ++ drivers/iio/imu/bmi160/bmi160_core.c | 5 ++--- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/iio/imu/bmi160/bmi160.h b/drivers/iio/imu/bmi160/bmi160.h index a82e040bd109..d29f1b5d1658 100644 --- a/drivers/iio/imu/bmi160/bmi160.h +++ b/drivers/iio/imu/bmi160/bmi160.h @@ -10,6 +10,8 @@ struct bmi160_data { struct iio_trigger *trig; struct regulator_bulk_data supplies[2]; struct iio_mount_matrix orientation; + /* Ensure natural alignment for timestamp if present */ + __le16 buf[16] __aligned(8); }; extern const struct regmap_config bmi160_regmap_config; diff --git a/drivers/iio/imu/bmi160/bmi160_core.c b/drivers/iio/imu/bmi160/bmi160_core.c index 222ebb26f013..86cfd75ea125 100644 --- a/drivers/iio/imu/bmi160/bmi160_core.c +++ b/drivers/iio/imu/bmi160/bmi160_core.c @@ -427,7 +427,6 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p) struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct bmi160_data *data = iio_priv(indio_dev); - __le16 buf[16]; /* 3 sens x 3 axis x __le16 + 3 x __le16 pad + 4 x __le16 tstamp */ int i, ret, j = 0, base = BMI160_REG_DATA_MAGN_XOUT_L; __le16 sample; @@ -438,10 +437,10 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p) &sample, sizeof(sample)); if (ret) goto done; - buf[j++] = sample; + data->buf[j++] = sample; } - iio_push_to_buffers_with_timestamp(indio_dev, buf, pf->timestamp); + iio_push_to_buffers_with_timestamp(indio_dev, data->buf, pf->timestamp); done: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED;