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authorAshay Jaiswal <ashayj@codeaurora.org>2015-01-08 16:24:25 +0300
committerMark Brown <broonie@kernel.org>2015-01-08 21:15:35 +0300
commit83b0302d347a49f951e904184afe57ac3723476e (patch)
treecf10bcad7c2f9915f436667256eea67bb3f35ddd /drivers/regulator
parent97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff)
downloadlinux-83b0302d347a49f951e904184afe57ac3723476e.tar.xz
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
Diffstat (limited to 'drivers/regulator')
-rw-r--r--drivers/regulator/core.c4
1 files changed, 3 insertions, 1 deletions
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(&regulator->list);
kfree(regulator);
rdev->open_count--;
rdev->exclusive = 0;
+ mutex_unlock(&rdev->mutex);
module_put(rdev->owner);
}