From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Lee Jones" , "Krzysztof Kozlowski" Date: Mon, 28 Apr 2014 02:11:22 +0100 Message-ID: Subject: [PATCH 3.2 52/94] mfd: max8997: Fix possible NULL pointer dereference on i2c_new_dummy error In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.58-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Krzysztof Kozlowski commit 97dc4ed3fa377ec91bb60ba98b70d645c2099384 upstream. During probe the driver allocates dummy I2C devices for RTC, haptic and MUIC 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 i2c_unregister_device(). If i2c_new_dummy() fails for RTC, haptic or MUIC devices, fail also the probe for main MFD driver. Signed-off-by: Krzysztof Kozlowski Signed-off-by: Lee Jones Signed-off-by: Ben Hutchings --- drivers/mfd/max8997.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/drivers/mfd/max8997.c +++ b/drivers/mfd/max8997.c @@ -148,10 +148,26 @@ static int max8997_i2c_probe(struct i2c_ mutex_init(&max8997->iolock); max8997->rtc = i2c_new_dummy(i2c->adapter, I2C_ADDR_RTC); + if (!max8997->rtc) { + dev_err(max8997->dev, "Failed to allocate I2C device for RTC\n"); + return -ENODEV; + } i2c_set_clientdata(max8997->rtc, max8997); + max8997->haptic = i2c_new_dummy(i2c->adapter, I2C_ADDR_HAPTIC); + if (!max8997->haptic) { + dev_err(max8997->dev, "Failed to allocate I2C device for Haptic\n"); + ret = -ENODEV; + goto err_i2c_haptic; + } i2c_set_clientdata(max8997->haptic, max8997); + max8997->muic = i2c_new_dummy(i2c->adapter, I2C_ADDR_MUIC); + if (!max8997->muic) { + dev_err(max8997->dev, "Failed to allocate I2C device for MUIC\n"); + ret = -ENODEV; + goto err_i2c_muic; + } i2c_set_clientdata(max8997->muic, max8997); pm_runtime_set_active(max8997->dev); @@ -178,7 +194,9 @@ static int max8997_i2c_probe(struct i2c_ err_mfd: mfd_remove_devices(max8997->dev); i2c_unregister_device(max8997->muic); +err_i2c_muic: i2c_unregister_device(max8997->haptic); +err_i2c_haptic: i2c_unregister_device(max8997->rtc); err: kfree(max8997);