[PATCH 3.12 035/182] mfd: 88pm860x: Fix possible NULL pointer dereference on i2c_new_dummy error

Jiri Slaby
2014-05-13T10:09:36Z

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

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

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

commit 159ce52a6b777fc82fa0b51c7440e25f9e4c6feb upstream.

During probe the driver allocates dummy I2C device for companion chip
with i2c_new_dummy() but it does not check the return value of this call.

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 regmap_init_i2c().

If i2c_new_dummy() fails for companion 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/88pm860x-core.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/mfd/88pm860x-core.c b/drivers/mfd/88pm860x-core.c
index 7ebe9ef1eba6..675f96b37643 100644
--- a/drivers/mfd/88pm860x-core.c
+++ b/drivers/mfd/88pm860x-core.c
@@ -1179,6 +1179,11 @@ static int pm860x_probe(struct i2c_client *client,
chip->companion_addr = pdata->companion_addr;
chip->companion = i2c_new_dummy(chip->client->adapter,
chip->companion_addr);
+ if (!chip->companion) {
+ dev_err(&client->dev,
+ "Failed to allocate I2C companion device\n");
+ return -ENODEV;
+ }
chip->regmap_companion = regmap_init_i2c(chip->companion,
&pm860x_regmap_config);
if (IS_ERR(chip->regmap_companion)) {
--
1.9.3