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: v3.2.67~62 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=3a8a47c5a3d71507abed60d05af1826f334d1e3e;hp=1c5b4c2b70b1c388e34874b2a3acda64f46bbc9a 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 [bwh: Backported to 3.2: - Adjust context - Don't touch the comment; __regulator_put() has not been split out of regulator_put() here] Signed-off-by: Ben Hutchings --- diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 6ec610c3b724..adba3d6495c0 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1314,12 +1314,14 @@ 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);