From patchwork Mon Jul 20 15:35:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 237359 Delivered-To: patch@linaro.org Received: by 2002:a92:d244:0:0:0:0:0 with SMTP id v4csp2103855ilg; Mon, 20 Jul 2020 08:57:55 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxTptntMBkkyV6uAD54aL/7LReyRgJOhPl51SCOlgFwbBsRQ6ot98YB9GeTtatGF7gWjMWD X-Received: by 2002:a17:906:3842:: with SMTP id w2mr21883462ejc.273.1595260675334; Mon, 20 Jul 2020 08:57:55 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1595260675; cv=none; d=google.com; s=arc-20160816; b=TZlhXN34yzgOcpVSZrIgeHM7heL9uBgB4AB2gP7QCW6h5/SPR+o+IgQ/W+vxLYfwXi Bf1vlmTHVRAHAwwP1vk2uA94V5EHY0zKibCiq32I94Qoi3fzVqpB4rDuxVaIr8r3VTGv 7oF7tfZs8ddikaOy0+xXgCrnCZpJyaYiieB2sfk39GnogaGcVCLN2pcuPHmtAkiM5h+h QIpx4tEFqoMdZaQRUaI5ek+YCiswTVFRghOoi7ZLOl8pqm1lfxOFfJHeitxjfudQoWNr MzLyfhac1c6vHFyuvaEJCEoP+KS6jXJs2BSwk/UIyErgYifWPRpzARKv2VZv8S+3GX6g k9WA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=n/Viv3BKqq8pIm+TYLRX1e59MtTTFZasgakEooSEyHw=; b=BehUuenRo9tvzcBEYujZUw0xvNb0wQ2o9KB3wt3e2ZqqUwoEl7djVztIA767bdmF8v 25Ik+tpNiv2tHw8wZ8m2vnJyKhnYh3QsoHMXqMCSd0oZ1xtxZXpd3iLCOQfpLVE8oLjh VmDZF58B6JGeAb217SDPzfRcZQdkYgqeArJ4KdSxcfWu7RJ4vbfl1na+C3nukQ+gHp7X 1OXVYzVw0/dL/9pMXlBtbZ1rWTZqvIKXEeR89Zom3KmbNwt31Mc1D2Shk+TlFv4hqZB4 FAHTncCZtDZre71KiL+fdJELGgj1ByZ2Ym95IDMxRRYys8iqpGz0Yslx35WdjkmFjeR1 EXTg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=hPbYSGjp; 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 Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id l7si10979731edv.475.2020.07.20.08.57.55; Mon, 20 Jul 2020 08:57:55 -0700 (PDT) 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=@kernel.org header.s=default header.b=hPbYSGjp; 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 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731690AbgGTP5y (ORCPT + 15 others); Mon, 20 Jul 2020 11:57:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:57912 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731948AbgGTP5w (ORCPT ); Mon, 20 Jul 2020 11:57:52 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A7FD02176B; Mon, 20 Jul 2020 15:57:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595260671; bh=gBJjacVL2m/4ejgMgslD8NKdAbwGMCJFnQvE0Zo+e6Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hPbYSGjp5vnrALz9T0RNTQfCjCR4elZHepOU47ACv0DNg5PET6CY+U8cMeu+qa8D6 KB1r98dU7nBaPRKg3ziYSJ7+vpYMFNz/zIuxr1QR52Bn3wJ/S3lOSlo7Vmi+t/oX15 m998H1IJ5hFZXBHjpXzV+G/2rdgwfKiZNf02AAKk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Lorenzo Bianconi , Jonathan Cameron , Stable@vger.kernel.org Subject: [PATCH 5.4 052/215] iio:humidity:hts221 Fix alignment and data leak issues Date: Mon, 20 Jul 2020 17:35:34 +0200 Message-Id: <20200720152822.680365104@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152820.122442056@linuxfoundation.org> References: <20200720152820.122442056@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jonathan Cameron commit 5c49056ad9f3c786f7716da2dd47e4488fc6bd25 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. Explicit alignment of ts needed to ensure consistent padding on all architectures (particularly x86_32 with it's 4 byte alignment of s64) Fixes: e4a70e3e7d84 ("iio: humidity: add support to hts221 rh/temp combo device") Reported-by: Lars-Peter Clausen Acked-by: Lorenzo Bianconi Signed-off-by: Jonathan Cameron Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/iio/humidity/hts221.h | 7 +++++-- drivers/iio/humidity/hts221_buffer.c | 9 +++++---- 2 files changed, 10 insertions(+), 6 deletions(-) --- a/drivers/iio/humidity/hts221.h +++ b/drivers/iio/humidity/hts221.h @@ -14,8 +14,6 @@ #include -#define HTS221_DATA_SIZE 2 - enum hts221_sensor_type { HTS221_SENSOR_H, HTS221_SENSOR_T, @@ -39,6 +37,11 @@ struct hts221_hw { bool enabled; u8 odr; + /* Ensure natural alignment of timestamp */ + struct { + __le16 channels[2]; + s64 ts __aligned(8); + } scan; }; extern const struct dev_pm_ops hts221_pm_ops; --- a/drivers/iio/humidity/hts221_buffer.c +++ b/drivers/iio/humidity/hts221_buffer.c @@ -162,7 +162,6 @@ static const struct iio_buffer_setup_ops static irqreturn_t hts221_buffer_handler_thread(int irq, void *p) { - u8 buffer[ALIGN(2 * HTS221_DATA_SIZE, sizeof(s64)) + sizeof(s64)]; struct iio_poll_func *pf = p; struct iio_dev *iio_dev = pf->indio_dev; struct hts221_hw *hw = iio_priv(iio_dev); @@ -172,18 +171,20 @@ static irqreturn_t hts221_buffer_handler /* humidity data */ ch = &iio_dev->channels[HTS221_SENSOR_H]; err = regmap_bulk_read(hw->regmap, ch->address, - buffer, HTS221_DATA_SIZE); + &hw->scan.channels[0], + sizeof(hw->scan.channels[0])); if (err < 0) goto out; /* temperature data */ ch = &iio_dev->channels[HTS221_SENSOR_T]; err = regmap_bulk_read(hw->regmap, ch->address, - buffer + HTS221_DATA_SIZE, HTS221_DATA_SIZE); + &hw->scan.channels[1], + sizeof(hw->scan.channels[1])); if (err < 0) goto out; - iio_push_to_buffers_with_timestamp(iio_dev, buffer, + iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan, iio_get_time_ns(iio_dev)); out: