From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 930E5C4361B for ; Sat, 5 Dec 2020 18:34:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 666322251D for ; Sat, 5 Dec 2020 18:34:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728082AbgLESec (ORCPT ); Sat, 5 Dec 2020 13:34:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:58734 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726600AbgLESe2 (ORCPT ); Sat, 5 Dec 2020 13:34:28 -0500 Subject: patch "iio:light:st_uvis25: Fix timestamp alignment and prevent data leak." added to staging-next DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1607183273; bh=fN9Ie3daN1lWwvAKMIwC+pQoTYvNaraD3u3qo5OQqtQ=; h=To:From:Date:From; b=PNXRXOwR55lzGiQyqpUPUn8qy7kEy8t0pE9N2gV4BzQKbKgFHVJ+eX+1klmJD/QSl LamfS9wOArX5MFeGDP2vyQSxipfcZSsDXT7PO6OWU7FZGLm24R60ffPmmDk4dl/4Gx fuhgRyop/M9/e1yxiwa/pYmaWp3G1qzG1IW+loos= To: Jonathan.Cameron@huawei.com, Stable@vger.kernel.org, alexandru.ardelean@analog.com, lars@metafoo.de, lorenzo@kernel.org From: Date: Sat, 05 Dec 2020 16:46:01 +0100 Message-ID: <16071831616774@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled iio:light:st_uvis25: Fix timestamp alignment and prevent data leak. to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-next branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will also be merged in the next major kernel release during the merge window. If you have any questions about this process, please let me know. >From d837a996f57c29a985177bc03b0e599082047f27 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Sun, 20 Sep 2020 12:27:36 +0100 Subject: iio:light:st_uvis25: Fix timestamp alignment and prevent data leak. 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() This data is allocated with kzalloc() so no data can leak apart from previous readings. A local unsigned int variable is used for the regmap call so it is clear there is no potential issue with writing into the padding of the structure. Fixes: 3025c8688c1e ("iio: light: add support for UVIS25 sensor") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Alexandru Ardelean Acked-by: Lorenzo Bianconi Cc: Link: https://lore.kernel.org/r/20200920112742.170751-3-jic23@kernel.org --- drivers/iio/light/st_uvis25.h | 5 +++++ drivers/iio/light/st_uvis25_core.c | 8 +++++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/iio/light/st_uvis25.h b/drivers/iio/light/st_uvis25.h index 78bc56aad129..283086887caf 100644 --- a/drivers/iio/light/st_uvis25.h +++ b/drivers/iio/light/st_uvis25.h @@ -27,6 +27,11 @@ struct st_uvis25_hw { struct iio_trigger *trig; bool enabled; int irq; + /* Ensure timestamp is naturally aligned */ + struct { + u8 chan; + s64 ts __aligned(8); + } scan; }; extern const struct dev_pm_ops st_uvis25_pm_ops; diff --git a/drivers/iio/light/st_uvis25_core.c b/drivers/iio/light/st_uvis25_core.c index a18a82e6bbf5..1055594b2276 100644 --- a/drivers/iio/light/st_uvis25_core.c +++ b/drivers/iio/light/st_uvis25_core.c @@ -232,17 +232,19 @@ static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = { static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p) { - u8 buffer[ALIGN(sizeof(u8), sizeof(s64)) + sizeof(s64)]; struct iio_poll_func *pf = p; struct iio_dev *iio_dev = pf->indio_dev; struct st_uvis25_hw *hw = iio_priv(iio_dev); + unsigned int val; int err; - err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, (int *)buffer); + err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, &val); if (err < 0) goto out; - iio_push_to_buffers_with_timestamp(iio_dev, buffer, + hw->scan.chan = val; + + iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan, iio_get_time_ns(iio_dev)); out: -- 2.29.2