diff options
author | Vladimir Zapolskiy <vz@mleia.com> | 2020-07-24 03:50:13 +0300 |
---|---|---|
committer | Mark Brown <broonie@kernel.org> | 2020-07-24 15:36:20 +0100 |
commit | 9177514ce34902b3adb2abd490b6ad05d1cfcb43 (patch) | |
tree | 563404c719424c5fb7284e7c0e38d45e7a564945 | |
parent | 2ca76b3e4954ea6bbb365005edc8d5237b488cf1 (diff) |
regulator: fix memory leak on error path of regulator_register()
The change corrects registration and deregistration on error path
of a regulator, the problem was manifested by a reported memory
leak on deferred probe:
as3722-regulator as3722-regulator: regulator 13 register failed -517
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xecc43740 (size 64):
comm "swapper/0", pid 1, jiffies 4294937640 (age 712.880s)
hex dump (first 32 bytes):
72 65 67 75 6c 61 74 6f 72 2e 32 34 00 5a 5a 5a regulator.24.ZZZ
5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
backtrace:
[<0c4c3d1c>] __kmalloc_track_caller+0x15c/0x2c0
[<40c0ad48>] kvasprintf+0x64/0xd4
[<109abd29>] kvasprintf_const+0x70/0x84
[<c4215946>] kobject_set_name_vargs+0x34/0xa8
[<62282ea2>] dev_set_name+0x40/0x64
[<a39b6757>] regulator_register+0x3a4/0x1344
[<16a9543f>] devm_regulator_register+0x4c/0x84
[<51a4c6a1>] as3722_regulator_probe+0x294/0x754
...
The memory leak problem was introduced as a side ef another fix in
regulator_register() error path, I believe that the proper fix is
to decouple device_register() function into its two compounds and
initialize a struct device before assigning any values to its fields
and then using it before actual registration of a device happens.
This lets to call put_device() safely after initialization, and, since
now a release callback is called, kfree(rdev->constraints) shall be
removed to exclude a double free condition.
Fixes: a3cde9534ebd ("regulator: core: fix regulator_register() error paths to properly release rdev")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Wen Yang <wenyang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20200724005013.23278-1-vz@mleia.com
Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r-- | drivers/regulator/core.c | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 196e344a84d3..75ff7c563c5d 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -5092,7 +5092,6 @@ 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; @@ -5221,10 +5220,12 @@ regulator_register(const struct regulator_desc *regulator_desc, } /* register with sysfs */ + device_initialize(&rdev->dev); rdev->dev.class = ®ulator_class; rdev->dev.parent = dev; dev_set_name(&rdev->dev, "regulator.%lu", (unsigned long) atomic_inc_return(®ulator_no)); + dev_set_drvdata(&rdev->dev, rdev); /* set regulator constraints */ if (init_data) @@ -5275,12 +5276,9 @@ regulator_register(const struct regulator_desc *regulator_desc, !rdev->desc->fixed_uV) rdev->is_switch = true; - dev_set_drvdata(&rdev->dev, rdev); - ret = device_register(&rdev->dev); - if (ret != 0) { - reg_device_fail = true; + ret = device_add(&rdev->dev); + if (ret != 0) goto unset_supplies; - } rdev_init_debugfs(rdev); @@ -5302,17 +5300,15 @@ unset_supplies: mutex_unlock(®ulator_list_mutex); wash: kfree(rdev->coupling_desc.coupled_rdevs); - kfree(rdev->constraints); mutex_lock(®ulator_list_mutex); regulator_ena_gpio_free(rdev); mutex_unlock(®ulator_list_mutex); + put_device(&rdev->dev); + rdev = NULL; clean: if (dangling_of_gpiod) gpiod_put(config->ena_gpiod); - if (reg_device_fail) - put_device(&rdev->dev); - else - kfree(rdev); + kfree(rdev); kfree(config); rinse: if (dangling_cfg_gpiod) |