Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757628AbbBFMVI (ORCPT ); Fri, 6 Feb 2015 07:21:08 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:41202 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755542AbbBFMCh (ORCPT ); Fri, 6 Feb 2015 07:02:37 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Ashay Jaiswal , Mark Brown , Luis Henriques Subject: [PATCH 3.16.y-ckt 079/135] regulator: core: fix race condition in regulator_put() Date: Fri, 6 Feb 2015 12:00:57 +0000 Message-Id: <1423224113-10958-80-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1423224113-10958-1-git-send-email-luis.henriques@canonical.com> References: <1423224113-10958-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2196 Lines: 63 3.16.7-ckt6 -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: Luis Henriques --- 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 4c1f999041dd..b4686ea6d66b 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1485,7 +1485,7 @@ struct regulator *regulator_get_optional(struct device *dev, const char *id) } EXPORT_SYMBOL_GPL(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; @@ -1500,12 +1500,14 @@ 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); } -- 2.1.4 -- 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/