[PATCH 3.12 039/182] mfd: max77693: Fix possible NULL pointer dereference on i2c_new_dummy error

Jiri Slaby
2014-05-13T10:05:57Z

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

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

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

commit ad09dd6a1f5d6244bd89314015af506ba7f9810a upstream.

During probe the driver allocates dummy I2C devices for MUIC and haptic
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 devm_regmap_init_i2c() and i2c_unregister_device().

If i2c_new_dummy() fails for MUIC or haptic 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: Jiri Slaby <jslaby@suse.cz>
---
drivers/mfd/max77693.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/max77693.c b/drivers/mfd/max77693.c
index c04723efc707..8abfd3f0af5b 100644
--- a/drivers/mfd/max77693.c
+++ b/drivers/mfd/max77693.c
@@ -149,9 +149,18 @@ static int max77693_i2c_probe(struct i2c_client *i2c,
dev_info(max77693->dev, "device ID: 0x%x\n", reg_data);

max77693->muic = i2c_new_dummy(i2c->adapter, I2C_ADDR_MUIC);
+ if (!max77693->muic) {
+ dev_err(max77693->dev, "Failed to allocate I2C device for MUIC\n");
+ return -ENODEV;
+ }
i2c_set_clientdata(max77693->muic, max77693);

max77693->haptic = i2c_new_dummy(i2c->adapter, I2C_ADDR_HAPTIC);
+ if (!max77693->haptic) {
+ dev_err(max77693->dev, "Failed to allocate I2C device for Haptic\n");
+ ret = -ENODEV;
+ goto err_i2c_haptic;
+ }
i2c_set_clientdata(max77693->haptic, max77693);

/*
@@ -187,8 +196,9 @@ err_mfd:
max77693_irq_exit(max77693);
err_irq:
err_regmap_muic:
- i2c_unregister_device(max77693->muic);
i2c_unregister_device(max77693->haptic);
+err_i2c_haptic:
+ i2c_unregister_device(max77693->muic);
return ret;
}

--
1.9.3