From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58510 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752089AbdGVNPj (ORCPT ); Sat, 22 Jul 2017 09:15:39 -0400 Subject: Patch "thermal: max77620: fix device-node reference imbalance" has been added to the 4.12-stable tree To: johan@kernel.org, gregkh@linuxfoundation.org, ldewangan@nvidia.com Cc: , From: Date: Sat, 22 Jul 2017 15:02:16 +0200 Message-ID: <1500728536150170@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled thermal: max77620: fix device-node reference imbalance to the 4.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: thermal-max77620-fix-device-node-reference-imbalance.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From c592fafbdbb6b1279b76a54722d1465ca77e5bde Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 6 Jun 2017 17:59:03 +0200 Subject: thermal: max77620: fix device-node reference imbalance From: Johan Hovold commit c592fafbdbb6b1279b76a54722d1465ca77e5bde upstream. The thermal child device reuses the parent MFD-device device-tree node when registering a thermal zone, but did not take a reference to the node. This leads to a reference imbalance, and potential use-after-free, when the node reference is dropped by the platform-bus device destructor (once for the child and later again for the parent). Fix this by dropping any reference already held to a device-tree node and getting a reference to the parent's node which will be balanced on reprobe or on platform-device release, whichever comes first. Note that simply clearing the of_node pointer on probe errors and on driver unbind would not allow the use of device-managed resources as specifically thermal_zone_of_sensor_unregister() claims that a valid device-tree node pointer is needed during deregistration (even if it currently does not seem to use it). Fixes: ec4664b3fd6d ("thermal: max77620: Add thermal driver for reporting junction temp") Cc: Laxman Dewangan Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/thermal/max77620_thermal.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/thermal/max77620_thermal.c +++ b/drivers/thermal/max77620_thermal.c @@ -104,8 +104,6 @@ static int max77620_thermal_probe(struct return -EINVAL; } - pdev->dev.of_node = pdev->dev.parent->of_node; - mtherm->dev = &pdev->dev; mtherm->rmap = dev_get_regmap(pdev->dev.parent, NULL); if (!mtherm->rmap) { @@ -113,6 +111,14 @@ static int max77620_thermal_probe(struct return -ENODEV; } + /* + * Drop any current reference to a device-tree node and get a + * reference to the parent's node which will be balanced on reprobe or + * on platform-device release. + */ + of_node_put(pdev->dev.of_node); + pdev->dev.of_node = of_node_get(pdev->dev.parent->of_node); + mtherm->tz_device = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, mtherm, &max77620_thermal_ops); if (IS_ERR(mtherm->tz_device)) { Patches currently in stable-queue which might be from johan@kernel.org are queue-4.12/nfc-nfcmrvl-use-nfc-device-for-firmware-download.patch queue-4.12/nfc-nfcmrvl-fix-firmware-management-initialisation.patch queue-4.12/nfc-nfcmrvl-do-not-use-device-managed-resources.patch queue-4.12/thermal-max77620-fix-device-node-reference-imbalance.patch queue-4.12/nfc-nfcmrvl_uart-add-missing-tty-device-sanity-check.patch queue-4.12/nfc-fix-broken-device-allocation.patch