Re: [PATCH 5/7] regulator: plug of_node leak in regulator_register()'s error path

[Vladimir Zapolskiy]

Hi Michał,

On 8/11/20 4:07 AM, Michał Mirosław wrote:
> By calling device_initialize() earlier and noting that kfree(NULL) is
> ok, we can save a bit of code in error handling and plug of_node leak.
> Fixed commit already did part of the work.
> 
> Cc: sta...@vger.kernel.org
> Fixes: 9177514ce349 ("regulator: fix memory leak on error path of 
> regulator_register()")
> Signed-off-by: Michał Mirosław 

thank you for the patch!

I was worried about a potentially remaining of_node reference leak,
but I was not able to reproduce it on practice without code fuzzing.

The change looks valid and it's a nice simplification.

Acked-by: Vladimir Zapolskiy 

--
Best wishes,
Vladimir

[PATCH 5/7] regulator: plug of_node leak in regulator_register()'s error path

[Michał Mirosław]

By calling device_initialize() earlier and noting that kfree(NULL) is
ok, we can save a bit of code in error handling and plug of_node leak.
Fixed commit already did part of the work.

Cc: sta...@vger.kernel.org
Fixes: 9177514ce349 ("regulator: fix memory leak on error path of 
regulator_register()")
Signed-off-by: Michał Mirosław 
---
 drivers/regulator/core.c | 13 -
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 0408c4e1d9a8..a9ff2ad55ee7 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -5137,6 +5137,7 @@ regulator_register(const struct regulator_desc 
*regulator_desc,
ret = -ENOMEM;
goto rinse;
}
+   device_initialize(>dev);
 
/*
 * Duplicate the config so the driver could override it after
@@ -5144,9 +5145,8 @@ regulator_register(const struct regulator_desc 
*regulator_desc,
 */
config = kmemdup(cfg, sizeof(*cfg), GFP_KERNEL);
if (config == NULL) {
-   kfree(rdev);
ret = -ENOMEM;
-   goto rinse;
+   goto clean;
}
 
init_data = regulator_of_get_init_data(dev, regulator_desc, config,
@@ -5158,10 +5158,8 @@ regulator_register(const struct regulator_desc 
*regulator_desc,
 * from a gpio extender or something else.
 */
if (PTR_ERR(init_data) == -EPROBE_DEFER) {
-   kfree(config);
-   kfree(rdev);
ret = -EPROBE_DEFER;
-   goto rinse;
+   goto clean;
}
 
/*
@@ -5214,7 +5212,6 @@ regulator_register(const struct regulator_desc 
*regulator_desc,
}
 
/* register with sysfs */
-   device_initialize(>dev);
rdev->dev.class = _class;
rdev->dev.parent = dev;
dev_set_name(>dev, "regulator.%lu",
@@ -5292,13 +5289,11 @@ regulator_register(const struct regulator_desc 
*regulator_desc,
mutex_lock(_list_mutex);
regulator_ena_gpio_free(rdev);
mutex_unlock(_list_mutex);
-   put_device(>dev);
-   rdev = NULL;
 clean:
if (dangling_of_gpiod)
gpiod_put(config->ena_gpiod);
-   kfree(rdev);
kfree(config);
+   put_device(>dev);
 rinse:
if (dangling_cfg_gpiod)
gpiod_put(cfg->ena_gpiod);
-- 
2.20.1