From 83b0302d347a49f951e904184afe57ac3723476e Mon Sep 17 00:00:00 2001 From: Ashay Jaiswal <ashayj@codeaurora.org> Date: Thu, 8 Jan 2015 18:54:25 +0530 Subject: [PATCH] regulator: core: fix race condition in regulator_put() 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 <ashayj@codeaurora.org> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org --- 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 e225711bb8bc..9c48fb32f660 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1488,7 +1488,7 @@ 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; @@ -1503,12 +1503,14 @@ 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); } -- 2.30.9