Unverified Commit a3cde953 authored Dec 01, 2019 by Wen Yang Committed by Mark Brown Dec 03, 2019

regulator: core: fix regulator_register() error paths to properly release rdev



There are several issues with the error handling code of
the regulator_register() function:
        ret = device_register(&rdev->dev);
        if (ret != 0) {
                put_device(&rdev->dev); --> rdev released
                goto unset_supplies;
        }
...
unset_supplies:
...
        unset_regulator_supplies(rdev); --> use-after-free
...
clean:
        if (dangling_of_gpiod)
                gpiod_put(config->ena_gpiod);
        kfree(rdev);                     --> double free

We add a variable to record the failure of device_register() and
move put_device() down a bit to avoid the above issues.

Fixes: c438b9d0 ("regulator: core: Move registration of regulator device")
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/20191201030250.38074-1-wenyang@linux.alibaba.com


Signed-off-by: Mark Brown <broonie@kernel.org>

parent 4affd79a

drivers/regulator/core.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -4998,6 +4998,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
		struct regulator_dev *rdev;
		bool dangling_cfg_gpiod = false;
		bool dangling_of_gpiod = false;
		bool reg_device_fail = false;
		struct device *dev;
		int ret, i;

		@@ -5183,7 +5184,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
		dev_set_drvdata(&rdev->dev, rdev);
		ret = device_register(&rdev->dev);
		if (ret != 0) {
		put_device(&rdev->dev);
		reg_device_fail = true;
		goto unset_supplies;
		}

		@@ -5213,6 +5214,9 @@ wash:
		clean:
		if (dangling_of_gpiod)
		gpiod_put(config->ena_gpiod);
		if (reg_device_fail)
		put_device(&rdev->dev);
		else
		kfree(rdev);
		kfree(config);
		rinse:

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