[PATCH 2/2] regulator: core: fix resource leak in regulator_register()

[Yang Yingliang <yangyingliang@huawei.com>]

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>
---
 drivers/regulator/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 4a7d8ec415e8..42b683963f9e 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -5641,10 +5641,11 @@ regulator_register(const struct regulator_desc *regulator_desc,
 	mutex_lock(&regulator_list_mutex);
 	unset_regulator_supplies(rdev);
 	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);
 	mutex_unlock(&regulator_list_mutex);
 	put_device(&rdev->dev);
-- 
2.25.1