From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Date: Tue, 11 Feb 2014 10:03:33 +0000 (+0100)
Subject: mfd: max8925: Fix possible NULL pointer dereference on i2c_new_dummy error
X-Git-Tag: firefly_0821_release~3679^2~2448
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=64ff251f373e35623e88333c1dc9ea118bbe857b;p=firefly-linux-kernel-4.4.55.git

mfd: max8925: Fix possible NULL pointer dereference on i2c_new_dummy error

commit 96cf3dedc491d2f1f66cc26217f2b06b0c7b6797 upstream.

During probe the driver allocates dummy I2C devices for RTC and ADC
with i2c_new_dummy() but it does not check the return value of this
calls.

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 i2c_unregister_device().

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

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/mfd/max8925-i2c.c b/drivers/mfd/max8925-i2c.c
index 92bbebd31598..c94d3337bdfd 100644
--- a/drivers/mfd/max8925-i2c.c
+++ b/drivers/mfd/max8925-i2c.c
@@ -180,9 +180,18 @@ static int max8925_probe(struct i2c_client *client,
 	mutex_init(&chip->io_lock);
 
 	chip->rtc = i2c_new_dummy(chip->i2c->adapter, RTC_I2C_ADDR);
+	if (!chip->rtc) {
+		dev_err(chip->dev, "Failed to allocate I2C device for RTC\n");
+		return -ENODEV;
+	}
 	i2c_set_clientdata(chip->rtc, chip);
 
 	chip->adc = i2c_new_dummy(chip->i2c->adapter, ADC_I2C_ADDR);
+	if (!chip->adc) {
+		dev_err(chip->dev, "Failed to allocate I2C device for ADC\n");
+		i2c_unregister_device(chip->rtc);
+		return -ENODEV;
+	}
 	i2c_set_clientdata(chip->adc, chip);
 
 	device_init_wakeup(&client->dev, 1);