regulator: fix use after free issue

This is caused by dereferencing 'rdev' after put_device() in
the _regulator_get()/_regulator_put() functions.
This patch just moves the put_device() down a bit to avoid the
issue.

Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20191124145835.25999-1-wenyang@linux.alibaba.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 5e6c629806e42548e31699c020de6c024f48e432..c80f3fd9532ddf7d16b5246ca27731f9c7863e17 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1937,8 +1937,8 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
        regulator = create_regulator(rdev, dev, id);
        if (regulator == NULL) {
                regulator = ERR_PTR(-ENOMEM);
-               put_device(&rdev->dev);
                module_put(rdev->owner);
+               put_device(&rdev->dev);
                return regulator;
        }
 
@@ -2059,13 +2059,13 @@ static void _regulator_put(struct regulator *regulator)
 
        rdev->open_count--;
        rdev->exclusive = 0;
-       put_device(&rdev->dev);
        regulator_unlock(rdev);
 
        kfree_const(regulator->supply_name);
        kfree(regulator);
 
        module_put(rdev->owner);
+       put_device(&rdev->dev);
 }
 
 /**