[PATCH] regulator: fix memory leak with repeated set_machine_constraints()

[Michał Mirosław]

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: sta...@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-li...@rere.qmqm.pl>
---
 drivers/regulator/core.c | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 8521f74ee75c..402a72a70eb1 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1290,7 +1290,6 @@ static int _regulator_do_enable(struct regulator_dev 
*rdev);
 /**
  * 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:
@@ -1298,21 +1297,11 @@ static int _regulator_do_enable(struct regulator_dev 
*rdev);
  * 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;
@@ -5121,7 +5110,6 @@ 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);
@@ -5260,14 +5248,23 @@ regulator_register(const struct regulator_desc 
*regulator_desc,
 
        /* 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 */
@@ -5276,7 +5273,7 @@ regulator_register(const struct regulator_desc 
*regulator_desc,
                 * 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));
-- 
2.20.1