Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965714AbbBQMBj (ORCPT ); Tue, 17 Feb 2015 07:01:39 -0500 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:39808 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756911AbbBQLfN (ORCPT ); Tue, 17 Feb 2015 06:35:13 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ashay Jaiswal , Mark Brown , Jiri Slaby Subject: [PATCH 3.12 048/122] regulator: core: fix race condition in regulator_put() Date: Tue, 17 Feb 2015 12:33:55 +0100 Message-Id: <28140574e151bbdbd34f28be4e656ea6b1b5ae9d.1424099973.git.jslaby@suse.cz> X-Mailer: git-send-email 2.2.2 In-Reply-To: <09e6fe32192a77f6e2e60cc0f4103e630c7ecf20.1424099973.git.jslaby@suse.cz> References: <09e6fe32192a77f6e2e60cc0f4103e630c7ecf20.1424099973.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2161 Lines: 63 From: Ashay Jaiswal 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- drivers/regulator/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index ea83084cb7d9..a2ce8e86ced7 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1474,7 +1474,7 @@ struct regulator *devm_regulator_get_optional(struct device *dev, } EXPORT_SYMBOL_GPL(devm_regulator_get_optional); -/* Locks held by regulator_put() */ +/* regulator_list_mutex lock held by regulator_put() */ static void _regulator_put(struct regulator *regulator) { struct regulator_dev *rdev; @@ -1489,12 +1489,14 @@ static void _regulator_put(struct regulator *regulator) /* 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); } -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/