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| author | Ashay Jaiswal <ashayj@codeaurora.org> | 2015-01-08 18:54:25 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-05 22:35:51 -0800 |
| commit | b17ab0146dc0842d1014304ee73914662993cfc9 (patch) | |
| tree | 75b879a6c0fdfe5fd1b220a3ac148d8795d3d0c8 /drivers | |
| parent | 03c5a83d8c13cf8d182290cb8771dab3a943cc35 (diff) | |
| download | lwn-b17ab0146dc0842d1014304ee73914662993cfc9.tar.gz lwn-b17ab0146dc0842d1014304ee73914662993cfc9.zip | |
regulator: core: fix race condition in regulator_put()
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 <ashayj@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/regulator/core.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index afca1bc24f26..b7984044232d 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1479,7 +1479,7 @@ 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; @@ -1494,12 +1494,14 @@ 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); } |