| From | lizf@kernel ... | Subject | [PATCH 3.4 118/176] regulator: core: fix race condition in regulator_put() | Date | Thu, 9 Apr 2015 16:46:06 +0800 |
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From: Ashay Jaiswal <ashayj@codeaurora.org>
3.4.107-rc1 review patch. If anyone has any objections, please let me know.
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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> [lizf: Backported to 3.4: - adjust context - no need to change the comment] Signed-off-by: Zefan Li <lizefan@huawei.com> --- drivers/regulator/core.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index c18f0fd..0d71557 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); -- 1.9.1
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