mfd: sec-core: Fix possible NULL pointer dereference when i2c_new_dummy error

During probe the sec-core driver allocates dummy I2C device for RTC with
i2c_new_dummy() but return value is not checked. In case of error
(i2c_new_device(): memory allocation failure or I2C address cannot be
used) this function returns NULL which is later used by
devm_regmap_init_i2c() or i2c_unregister_device().

If i2c_new_dummy() fails for RTC device, fail also the probe for main
MFD driver.

Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/mfd/sec-core.c b/drivers/mfd/sec-core.c
index a4df76c160f89b4056994c83b59c5ea0ee19b008..d163c66edebb9bf5df6dc5ac1ae6e846b7fc18e0 100644 (file)
--- a/drivers/mfd/sec-core.c
+++ b/drivers/mfd/sec-core.c
@@ -298,6 +298,10 @@ static int sec_pmic_probe(struct i2c_client *i2c,
        }
 
        sec_pmic->rtc = i2c_new_dummy(i2c->adapter, RTC_I2C_ADDR);
+       if (!sec_pmic->rtc) {
+               dev_err(&i2c->dev, "Failed to allocate I2C for RTC\n");
+               return -ENODEV;
+       }
        i2c_set_clientdata(sec_pmic->rtc, sec_pmic);
 
        sec_pmic->regmap_rtc = devm_regmap_init_i2c(sec_pmic->rtc, regmap_rtc);