[PATCH resend] regulator: core: fix resource leak in regulator_register()

[PATCH resend] regulator: core: fix resource leak in regulator_register()

[Yang Yingliang]

I got some resource leak reports while doing fault injection test:

  OF: ERROR: memory leak, expected refcount 1 instead of 100,
  of_node_get()/of_node_put() unbalanced - destroy cset entry:
  attach overlay node /i2c/pmic@64/regulators/buck1

unreferenced object 0xffff88810deea000 (size 512):
  comm "490-i2c-rt5190a", pid 253, jiffies 4294859840 (age 5061.046s)
  hex dump (first 32 bytes):
    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
    ff ff ff ff ff ff ff ff a0 1e 00 a1 ff ff ff ff  ................
  backtrace:
    [<00000000d78541e2>] kmalloc_trace+0x21/0x110
    [<00000000b343d153>] device_private_init+0x32/0xd0
    [<00000000be1f0c70>] device_add+0xb2d/0x1030
    [<00000000e3e6344d>] regulator_register+0xaf2/0x12a0
    [<00000000e2f5e754>] devm_regulator_register+0x57/0xb0
    [<000000008b898197>] rt5190a_probe+0x52a/0x861 [rt5190a_regulator]

unreferenced object 0xffff88810b617b80 (size 32):
  comm "490-i2c-rt5190a", pid 253, jiffies 4294859904 (age 5060.983s)
  hex dump (first 32 bytes):
    72 65 67 75 6c 61 74 6f 72 2e 32 38 36 38 2d 53  regulator.2868-S
    55 50 50 4c 59 00 ff ff 29 00 00 00 2b 00 00 00  UPPLY...)...+...
  backtrace:
    [<000000009da9280d>] __kmalloc_node_track_caller+0x44/0x1b0
    [<0000000025c6a4e5>] kstrdup+0x3a/0x70
    [<00000000790efb69>] create_regulator+0xc0/0x4e0
    [<0000000005ed203a>] regulator_resolve_supply+0x2d4/0x440
    [<0000000045796214>] regulator_register+0x10b3/0x12a0
    [<00000000e2f5e754>] devm_regulator_register+0x57/0xb0
    [<000000008b898197>] rt5190a_probe+0x52a/0x861 [rt5190a_regulator]

After calling regulator_resolve_supply(), the 'rdev->supply' is set
by set_supply(), after this set, in the error path, the resources
need be released, so call regulator_put() to avoid the leaks.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Fixes: 8a866d527ac0 ("regulator: core: Resolve supply name earlier to prevent double-init")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
Based on commit a4412fdd49dc ("error-injection: Add prompt for function error injection")
---
 drivers/regulator/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index e8c00a884f1f..5e78a5b868db 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -5641,6 +5641,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
 	regulator_remove_coupling(rdev);
 	mutex_unlock(&regulator_list_mutex);
 wash:
+	regulator_put(rdev->supply);
 	kfree(rdev->coupling_desc.coupled_rdevs);
 	mutex_lock(&regulator_list_mutex);
 	regulator_ena_gpio_free(rdev);
-- 
2.25.1

Re: [PATCH resend] regulator: core: fix resource leak in regulator_register()

[Mark Brown]

On Fri, 2 Dec 2022 10:51:11 +0800, Yang Yingliang wrote:
> I got some resource leak reports while doing fault injection test:
> 
>   OF: ERROR: memory leak, expected refcount 1 instead of 100,
>   of_node_get()/of_node_put() unbalanced - destroy cset entry:
>   attach overlay node /i2c/pmic@64/regulators/buck1
> 
> unreferenced object 0xffff88810deea000 (size 512):
>   comm "490-i2c-rt5190a", pid 253, jiffies 4294859840 (age 5061.046s)
>   hex dump (first 32 bytes):
>     00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
>     ff ff ff ff ff ff ff ff a0 1e 00 a1 ff ff ff ff  ................
>   backtrace:
>     [<00000000d78541e2>] kmalloc_trace+0x21/0x110
>     [<00000000b343d153>] device_private_init+0x32/0xd0
>     [<00000000be1f0c70>] device_add+0xb2d/0x1030
>     [<00000000e3e6344d>] regulator_register+0xaf2/0x12a0
>     [<00000000e2f5e754>] devm_regulator_register+0x57/0xb0
>     [<000000008b898197>] rt5190a_probe+0x52a/0x861 [rt5190a_regulator]
> 
> [...]

Applied to

   broonie/regulator.git for-next

Thanks!

[1/1] regulator: core: fix resource leak in regulator_register()
      commit: ba62319a42c50e6254e98b3f316464fac8e77968

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark