[PATCH 3.12 034/182] mfd: sec-core: Fix possible NULL pointer dereference when i2c_new_dummy error

Jiri Slaby
2014-05-13T10:09:32Z

From: Krzysztof Kozlowski <k.kozlowski@samsung.com>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

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@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
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 f530e4b73f19..d02546b0a8cc 100644
--- a/drivers/mfd/sec-core.c
+++ b/drivers/mfd/sec-core.c
@@ -274,6 +274,10 @@ 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)
--
1.9.3