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

[Kamal Mostafa]

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-3.13.y-queue branch of the 3.13.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-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.1.

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

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 0357be97a02440c95cf71740790569eed102e49a 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: Kamal Mostafa <kamal 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 54cc255..c62cc96 100644
--- a/drivers/mfd/sec-core.c
+++ b/drivers/mfd/sec-core.c
@@ -280,6 +280,10 @@ 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,
--
1.9.1