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[23.128.96.18]) by mx.google.com with ESMTP id y5si11201992edw.306.2020.07.20.08.52.18; Mon, 20 Jul 2020 08:52:18 -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=ffhlf+wy; 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 S1731348AbgGTPwR (ORCPT + 15 others); Mon, 20 Jul 2020 11:52:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:49924 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731323AbgGTPwN (ORCPT ); Mon, 20 Jul 2020 11:52:13 -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 7DC9722D3E; Mon, 20 Jul 2020 15:52:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595260333; bh=eVx2whG+iEhdi/wNAA8mHJvtFWijfFiSbn2YqjBTA2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ffhlf+wyWKlt1EOsFMRQxL6uqruTbLcx3XxYiM2ZZ1nIkGOLsfoHASzXtyNWHiKhu 790JoGvzUVGDpSz6QX1HzLyeGmTRS8YVcmy/YRSmqEpu3/9uOcbsF17aDKfDmHDbtN 0Pa0IESpTlXc8/4qTOP7rJxcf4Tlz75XzPpudK2Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Jonathan Cameron , Tomasz Duszynski , Stable@vger.kernel.org Subject: [PATCH 4.19 035/133] iio:pressure:ms5611 Fix buffer element alignment Date: Mon, 20 Jul 2020 17:36:22 +0200 Message-Id: <20200720152805.415751582@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152803.732195882@linuxfoundation.org> References: <20200720152803.732195882@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 8db4afe163bbdd93dca6fcefbb831ef12ecc6b4d 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. Here there is no data leak possibility so use an explicit structure on the stack to ensure alignment and nice readable fashion. The forced alignment of ts isn't strictly necessary in this driver as the padding will be correct anyway (there isn't any). However it is probably less fragile to have it there and it acts as documentation of the requirement. Fixes: 713bbb4efb9dc ("iio: pressure: ms5611: Add triggered buffer support") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Acked-by: Tomasz Duszynski Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/iio/pressure/ms5611_core.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/iio/pressure/ms5611_core.c +++ b/drivers/iio/pressure/ms5611_core.c @@ -215,16 +215,21 @@ static irqreturn_t ms5611_trigger_handle struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct ms5611_state *st = iio_priv(indio_dev); - s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */ + /* Ensure buffer elements are naturally aligned */ + struct { + s32 channels[2]; + s64 ts __aligned(8); + } scan; int ret; mutex_lock(&st->lock); - ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]); + ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1], + &scan.channels[0]); mutex_unlock(&st->lock); if (ret < 0) goto err; - iio_push_to_buffers_with_timestamp(indio_dev, buf, + iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev)); err: