regulator: act8865: fix parsing of platform data

The driver loops through all available regulators (ACT8865_REG_NUM)
and accesses pdata->regulators[i].platform_data without checking the
actual value of num_regulators in platform data, potentially causing a
invalid memory access.

Fix this and look up the regulator init_data by id in platform data.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Tested-by Wenyou.Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 21 insertions, 8 deletions

diff --git a/drivers/regulator/act8865-regulator.c b/drivers/regulator/act8865-regulator.c
index b92d7dd01a18..fe2c038f8cbc 100644
--- a/drivers/regulator/act8865-regulator.c
+++ b/drivers/regulator/act8865-regulator.c
@@ -252,6 +252,22 @@ static inline int act8865_pdata_from_dt(struct device *dev,
 }
 #endif
 
+static struct regulator_init_data
+*act8865_get_init_data(int id, struct act8865_platform_data *pdata)
+{
+        int i;
+
+        if (!pdata)
+                return NULL;
+
+        for (i = 0; i < pdata->num_regulators; i++) {
+                if (pdata->regulators[i].id == id)
+                        return pdata->regulators[i].platform_data;
+        }
+
+        return NULL;
+}
+
 static int act8865_pmic_probe(struct i2c_client *client,
                            const struct i2c_device_id *i2c_id)
 {
@@ -261,7 +277,7 @@ static int act8865_pmic_probe(struct i2c_client *client,
         struct regulator_config config = { };
         struct act8865 *act8865;
         struct device_node *of_node[ACT8865_REG_NUM];
-        int i, id;
+        int i;
         int ret = -EINVAL;
         int error;
 
@@ -299,20 +315,17 @@ static int act8865_pmic_probe(struct i2c_client *client,
 
         /* Finally register devices */
         for (i = 0; i < ACT8865_REG_NUM; i++) {
-
-                id = pdata->regulators[i].id;
+                const struct regulator_desc *desc = &act8865_reg[i];
 
                 config.dev = dev;
-                config.init_data = pdata->regulators[i].platform_data;
+                config.init_data = act8865_get_init_data(desc->id, pdata);
                 config.of_node = of_node[i];
                 config.driver_data = act8865;
                 config.regmap = act8865->regmap;
 
-                rdev = devm_regulator_register(&client->dev, &act8865_reg[i],
-                                               &config);
+                rdev = devm_regulator_register(&client->dev, desc, &config);
                 if (IS_ERR(rdev)) {
-                        dev_err(dev, "failed to register %s\n",
-                                act8865_reg[id].name);
+                        dev_err(dev, "failed to register %s\n", desc->name);
                         return PTR_ERR(rdev);
                 }
         }