[3.11.y.z extended stable] Patch "mfd: sec-core: Fix possible NULL pointer dereference when i2c_new_dummy error" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

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

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 4b5718e3f1f86c003d7270c75d1e0f5a15f608df Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Date: Tue, 11 Feb 2014 10:12:25 +0100
Subject: mfd: sec-core: Fix possible NULL pointer dereference when
 i2c_new_dummy error

commit 65aba1e04916d72b30c028730a1e31860c225412 upstream.

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.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Signed-off-by: Lee Jones <lee.jones at linaro.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/mfd/sec-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mfd/sec-core.c b/drivers/mfd/sec-core.c
index 7976768..ab8858d 100644
--- a/drivers/mfd/sec-core.c
+++ b/drivers/mfd/sec-core.c
@@ -238,6 +238,10 @@ 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);

 	if (pdata && pdata->cfg_pmic_irq)
--
1.9.1