[PATCH 4.19 79/91] regulator: fix memory leak with repeated set_machine_constraints()

Greg Kroah-Hartman
2020-11-23T12:33:51Z

From: Michał Mirosław <mirq-linux@rere.qmqm.pl>

commit 57a6ad482af256b2a13de14194fb8f67c1a65f10 upstream.

Fixed commit introduced a possible second call to
set_machine_constraints() and that allocates memory for
rdev->constraints. Move the allocation to the caller so
it's easier to manage and done once.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1
Link: https://lore.kernel.org/r/78c3d4016cebc08d441aad18cb924b4e4d9cf9df.1605226675.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/regulator/core.c | 29 +++++++++++++----------------
1 file changed, 13 insertions(+), 16 deletions(-)

--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1091,7 +1091,6 @@ static int _regulator_do_enable(struct r
/**
* set_machine_constraints - sets regulator constraints
* @rdev: regulator source
- * @constraints: constraints to apply
*
* Allows platform initialisation code to define and constrain
* regulator circuits e.g. valid voltage/current ranges, etc. NOTE:
@@ -1099,21 +1098,11 @@ static int _regulator_do_enable(struct r
* regulator operations to proceed i.e. set_voltage, set_current_limit,
* set_mode.
*/
-static int set_machine_constraints(struct regulator_dev *rdev,
- const struct regulation_constraints *constraints)
+static int set_machine_constraints(struct regulator_dev *rdev)
{
int ret = 0;
const struct regulator_ops *ops = rdev->desc->ops;

- if (constraints)
- rdev->constraints = kmemdup(constraints, sizeof(*constraints),
- GFP_KERNEL);
- else
- rdev->constraints = kzalloc(sizeof(*constraints),
- GFP_KERNEL);
- if (!rdev->constraints)
- return -ENOMEM;
-
ret = machine_constraints_voltage(rdev, rdev->constraints);
if (ret != 0)
return ret;
@@ -4257,7 +4246,6 @@ struct regulator_dev *
regulator_register(const struct regulator_desc *regulator_desc,
const struct regulator_config *cfg)
{
- const struct regulation_constraints *constraints = NULL;
const struct regulator_init_data *init_data;
struct regulator_config *config = NULL;
static atomic_t regulator_no = ATOMIC_INIT(-1);
@@ -4358,14 +4346,23 @@ regulator_register(const struct regulato

/* set regulator constraints */
if (init_data)
- constraints = &init_data->constraints;
+ rdev->constraints = kmemdup(&init_data->constraints,
+ sizeof(*rdev->constraints),
+ GFP_KERNEL);
+ else
+ rdev->constraints = kzalloc(sizeof(*rdev->constraints),
+ GFP_KERNEL);
+ if (!rdev->constraints) {
+ ret = -ENOMEM;
+ goto wash;
+ }

if (init_data && init_data->supply_regulator)
rdev->supply_name = init_data->supply_regulator;
else if (regulator_desc->supply_name)
rdev->supply_name = regulator_desc->supply_name;

- ret = set_machine_constraints(rdev, constraints);
+ ret = set_machine_constraints(rdev);
if (ret == -EPROBE_DEFER) {
/* Regulator might be in bypass mode and so needs its supply
* to set the constraints */
@@ -4374,7 +4371,7 @@ regulator_register(const struct regulato
* that is just being created */
ret = regulator_resolve_supply(rdev);
if (!ret)
- ret = set_machine_constraints(rdev, constraints);
+ ret = set_machine_constraints(rdev);
else
rdev_dbg(rdev, "unable to resolve supply early: %pe\n",
ERR_PTR(ret));