From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933981AbbBCXZh (ORCPT ); Tue, 3 Feb 2015 18:25:37 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:55344 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933504AbbBCXZU (ORCPT ); Tue, 3 Feb 2015 18:25:20 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ashay Jaiswal , Mark Brown Subject: [PATCH 3.10 16/51] regulator: core: fix race condition in regulator_put() Date: Tue, 3 Feb 2015 15:16:58 -0800 Message-Id: <20150203231725.079956561@linuxfoundation.org> X-Mailer: git-send-email 2.2.2 In-Reply-To: <20150203231724.582537862@linuxfoundation.org> References: <20150203231724.582537862@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ashay Jaiswal commit 83b0302d347a49f951e904184afe57ac3723476e upstream. The regulator framework maintains a list of consumer regulators for a regulator device and protects it from concurrent access using the regulator device's mutex lock. In the case of regulator_put() the consumer is removed and regulator device's parameters are updated without holding the regulator device's mutex. This would lead to a race condition between the regulator_put() and any function which traverses the consumer list or modifies regulator device's parameters. Fix this race condition by holding the regulator device's mutex in case of regulator_put. Signed-off-by: Ashay Jaiswal Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/regulator/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1410,7 +1410,7 @@ struct regulator *regulator_get_exclusiv } EXPORT_SYMBOL_GPL(regulator_get_exclusive); -/* Locks held by regulator_put() */ +/* regulator_list_mutex lock held by regulator_put() */ static void _regulator_put(struct regulator *regulator) { struct regulator_dev *rdev; @@ -1425,12 +1425,14 @@ static void _regulator_put(struct regula /* remove any sysfs entries */ if (regulator->dev) sysfs_remove_link(&rdev->dev.kobj, regulator->supply_name); + mutex_lock(&rdev->mutex); kfree(regulator->supply_name); list_del(®ulator->list); kfree(regulator); rdev->open_count--; rdev->exclusive = 0; + mutex_unlock(&rdev->mutex); module_put(rdev->owner); }