From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Krzysztof Kozlowski , Lee Jones , Kamal Mostafa Subject: [PATCH 3.8 080/133] mfd: max77686: Fix possible NULL pointer dereference on i2c_new_dummy error Date: Tue, 22 Apr 2014 13:13:38 -0700 Message-Id: <1398197671-12786-81-git-send-email-kamal@canonical.com> In-Reply-To: <1398197671-12786-1-git-send-email-kamal@canonical.com> References: <1398197671-12786-1-git-send-email-kamal@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8.13.22 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Krzysztof Kozlowski commit b9e183a1d495cd65412abe0f9df19b151716bfe7 upstream. During probe the driver allocates dummy I2C device for RTC 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 i2c_unregister_device(). If i2c_new_dummy() fails for RTC device, fail also the probe for main MFD driver. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Lee Jones Signed-off-by: Kamal Mostafa --- drivers/mfd/max77686.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/mfd/max77686.c b/drivers/mfd/max77686.c index 5b6f118..dbfd0f1 100644 --- a/drivers/mfd/max77686.c +++ b/drivers/mfd/max77686.c @@ -121,6 +121,10 @@ static int max77686_i2c_probe(struct i2c_client *i2c, dev_info(max77686->dev, "device found\n"); max77686->rtc = i2c_new_dummy(i2c->adapter, I2C_ADDR_RTC); + if (!max77686->rtc) { + dev_err(max77686->dev, "Failed to allocate I2C device for RTC\n"); + return -ENODEV; + } i2c_set_clientdata(max77686->rtc, max77686); max77686_irq_init(max77686); -- 1.9.1