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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 B5DE6C433E2 for ; Tue, 9 Jun 2020 18:01:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 99D4620734 for ; Tue, 9 Jun 2020 18:01:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591725715; bh=tJ7i3gI0/ijEe7QVglU/MZNhpV1Jc+al4aF2FGTCKJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0dRsLnc895fShXfq5p8D6+O37piuz7XJrGUFFysNsmdkB3zPs0VxyDAn50MihvbjS MwVmcWfudDBnOqFEzQyqN8BJ+L8pRXUnl35RVWxVUx08EKuqQ+Xn0rMlyrZQkLcABq QFYUQtEJkmPSsXm59FbyCOgHqws3NS15+sLSvoH4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387826AbgFISBy (ORCPT ); Tue, 9 Jun 2020 14:01:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:45284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731629AbgFIRx6 (ORCPT ); Tue, 9 Jun 2020 13:53:58 -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 B188D20774; Tue, 9 Jun 2020 17:53:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591725237; bh=tJ7i3gI0/ijEe7QVglU/MZNhpV1Jc+al4aF2FGTCKJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HH6LvVGATvXuYASpVir3jQF2Ssz1mej/7F69ejj9R/ce8autHCgtp52UZiF/10rle 6IKlPZYyWGF8gsf9h0nei2VBRpnfJTjfJszMGQQo8HXVaWP/ZTQiFc4xYZUGH6GnGA PpoV7EqgEQonVwFuoJ6iwQjfBFj9mfoJDUba6cyU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Stable@vger.kernel.org, Tomasz Duszynski Subject: [PATCH 5.6 25/41] iio:chemical:pms7003: Fix timestamp alignment and prevent data leak. Date: Tue, 9 Jun 2020 19:45:27 +0200 Message-Id: <20200609174114.531191397@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200609174112.129412236@linuxfoundation.org> References: <20200609174112.129412236@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jonathan Cameron commit 13e945631c2ffb946c0af342812a3cd39227de6e 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 with alignment explicitly requested. This data is allocated with kzalloc so no data can leak appart from previous readings. Fixes: a1d642266c14 ("iio: chemical: add support for Plantower PMS7003 sensor") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Cc: Acked-by: Tomasz Duszynski Signed-off-by: Greg Kroah-Hartman --- drivers/iio/chemical/pms7003.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) --- a/drivers/iio/chemical/pms7003.c +++ b/drivers/iio/chemical/pms7003.c @@ -73,6 +73,11 @@ struct pms7003_state { struct pms7003_frame frame; struct completion frame_ready; struct mutex lock; /* must be held whenever state gets touched */ + /* Used to construct scan to push to the IIO buffer */ + struct { + u16 data[3]; /* PM1, PM2P5, PM10 */ + s64 ts; + } scan; }; static int pms7003_do_cmd(struct pms7003_state *state, enum pms7003_cmd cmd) @@ -104,7 +109,6 @@ static irqreturn_t pms7003_trigger_handl struct iio_dev *indio_dev = pf->indio_dev; struct pms7003_state *state = iio_priv(indio_dev); struct pms7003_frame *frame = &state->frame; - u16 data[3 + 1 + 4]; /* PM1, PM2P5, PM10, padding, timestamp */ int ret; mutex_lock(&state->lock); @@ -114,12 +118,15 @@ static irqreturn_t pms7003_trigger_handl goto err; } - data[PM1] = pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET); - data[PM2P5] = pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET); - data[PM10] = pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET); + state->scan.data[PM1] = + pms7003_get_pm(frame->data + PMS7003_PM1_OFFSET); + state->scan.data[PM2P5] = + pms7003_get_pm(frame->data + PMS7003_PM2P5_OFFSET); + state->scan.data[PM10] = + pms7003_get_pm(frame->data + PMS7003_PM10_OFFSET); mutex_unlock(&state->lock); - iio_push_to_buffers_with_timestamp(indio_dev, data, + iio_push_to_buffers_with_timestamp(indio_dev, &state->scan, iio_get_time_ns(indio_dev)); err: iio_trigger_notify_done(indio_dev->trig);