From: Ashay Jaiswal Date: Thu, 8 Jan 2015 13:24:25 +0000 (+0530) Subject: regulator: core: fix race condition in regulator_put() X-Git-Tag: v3.4.107~60 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8f108b362bb02742f8bfac6961c4521c4dd807bd;p=thirdparty%2Fkernel%2Fstable.git 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 Signed-off-by: Mark Brown [lizf: Backported to 3.4: - adjust context - no need to change the comment] Signed-off-by: Zefan Li --- diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index c18f0fd1577fd..0d71557cf7a3f 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1395,12 +1395,14 @@ void regulator_put(struct regulator *regulator) device_remove_file(regulator->dev, ®ulator->dev_attr); kfree(regulator->dev_attr.attr.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); mutex_unlock(®ulator_list_mutex);