regulator: core: fix kobject release warning and memory leak in regulator_register()

[ Upstream commit 5f4b204b6b8153923d5be8002c5f7082985d153f ]

Here is a warning report about lack of registered release()
from kobject lib:

Device '(null)' does not have a release() function, it is broken and must be fixed.
WARNING: CPU: 0 PID: 48430 at drivers/base/core.c:2332 device_release+0x104/0x120
Call Trace:
 kobject_put+0xdc/0x180
 put_device+0x1b/0x30
 regulator_register+0x651/0x1170
 devm_regulator_register+0x4f/0xb0

When regulator_register() returns fail and directly goto `clean` symbol,
rdev->dev has not registered release() function yet (which is registered
by regulator_class in the following), so rdev needs to be freed manually.
If rdev->dev.of_node is not NULL, which means the of_node has gotten by
regulator_of_get_init_data(), it needs to call of_node_put() to avoid
refcount leak.

Otherwise, only calling put_device() would lead memory leak of rdev
in further:

unreferenced object 0xffff88810d0b1000 (size 2048):
  comm "107-i2c-rtq6752", pid 48430, jiffies 4342258431 (age 1341.780s)
  backtrace:
    kmalloc_trace+0x22/0x110
    regulator_register+0x184/0x1170
    devm_regulator_register+0x4f/0xb0

When regulator_register() returns fail and goto `wash` symbol,
rdev->dev has registered release() function, so directly call
put_device() to cleanup everything.

Fixes: d3c731564e09 ("regulator: plug of_node leak in regulator_register()'s error path")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Link: https://lore.kernel.org/r/20221116074339.1024240-1-zengheng4@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index aa4d78b..fd61c5c 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -5549,11 +5549,15 @@ wash:
        mutex_lock(&regulator_list_mutex);
        regulator_ena_gpio_free(rdev);
        mutex_unlock(&regulator_list_mutex);
+       put_device(&rdev->dev);
+       rdev = NULL;
 clean:
        if (dangling_of_gpiod)
                gpiod_put(config->ena_gpiod);
+       if (rdev && rdev->dev.of_node)
+               of_node_put(rdev->dev.of_node);
+       kfree(rdev);
        kfree(config);
-       put_device(&rdev->dev);
 rinse:
        if (dangling_cfg_gpiod)
                gpiod_put(cfg->ena_gpiod);