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[23.128.96.18]) by mx.google.com with ESMTP id r23si10730077eja.287.2020.07.20.08.50.52; Mon, 20 Jul 2020 08:50:53 -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=vsvGioOl; 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 S1730427AbgGTPuo (ORCPT + 15 others); Mon, 20 Jul 2020 11:50:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:47272 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731148AbgGTPum (ORCPT ); Mon, 20 Jul 2020 11:50:42 -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 D651E206E9; Mon, 20 Jul 2020 15:50:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595260241; bh=bYcsp+lTAjYQXjg17ZAbSyfn2+pSwrVpblngizYvBnQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vsvGioOlssbVPZ78droZfVkvWIqqm1p58xHXC+B8uzbCVkzusX/TenLU18S+QyBUI XBVgIUeixFGsdQp7WFlISI9gaBHnhJFSVD0ayENr1ieDUXUJWdXBvGfBzvc4wFa4vM AKjjjjrGwt88uQvEvhW5PmbaukuKihOi1b4hkcDM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Matt Ranostay , Alison Schofield , Jonathan Cameron , Stable@vger.kernel.org Subject: [PATCH 4.19 030/133] iio:humidity:hdc100x Fix alignment and data leak issues Date: Mon, 20 Jul 2020 17:36:17 +0200 Message-Id: <20200720152805.191228617@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 ea5e7a7bb6205d24371373cd80325db1bc15eded 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. Fixes: 16bf793f86b2 ("iio: humidity: hdc100x: add triggered buffer support for HDC100X") Reported-by: Lars-Peter Clausen Acked-by: Matt Ranostay Cc: Alison Schofield Signed-off-by: Jonathan Cameron Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/iio/humidity/hdc100x.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/iio/humidity/hdc100x.c +++ b/drivers/iio/humidity/hdc100x.c @@ -38,6 +38,11 @@ struct hdc100x_data { /* integration time of the sensor */ int adc_int_us[2]; + /* Ensure natural alignment of timestamp */ + struct { + __be16 channels[2]; + s64 ts __aligned(8); + } scan; }; /* integration time in us */ @@ -319,7 +324,6 @@ static irqreturn_t hdc100x_trigger_handl struct i2c_client *client = data->client; int delay = data->adc_int_us[0] + data->adc_int_us[1]; int ret; - s16 buf[8]; /* 2x s16 + padding + 8 byte timestamp */ /* dual read starts at temp register */ mutex_lock(&data->lock); @@ -330,13 +334,13 @@ static irqreturn_t hdc100x_trigger_handl } usleep_range(delay, delay + 1000); - ret = i2c_master_recv(client, (u8 *)buf, 4); + ret = i2c_master_recv(client, (u8 *)data->scan.channels, 4); if (ret < 0) { dev_err(&client->dev, "cannot read sensor data\n"); goto err; } - iio_push_to_buffers_with_timestamp(indio_dev, buf, + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, iio_get_time_ns(indio_dev)); err: mutex_unlock(&data->lock);