From 8302532f47bb6c3aa1ed2043d30187ca307f176a Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 4 Feb 2022 17:59:20 +0200 Subject: [PATCH] i2c: smbus: Check for parent device before dereference MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit An I²C adapter might be instantiated without parent. In such case there is no property can be retrieved. Skip SMBus alert setup when this happens. Fixes: a263a84088f6 ("i2c: smbus: Use device_*() functions instead of of_*()") Reported-by: syzbot+0591ccf54ee05344e4eb@syzkaller.appspotmail.com Signed-off-by: Andy Shevchenko Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core-smbus.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c index 053b215..e3b96fc 100644 --- a/drivers/i2c/i2c-core-smbus.c +++ b/drivers/i2c/i2c-core-smbus.c @@ -705,10 +705,14 @@ EXPORT_SYMBOL_GPL(i2c_new_smbus_alert_device); #if IS_ENABLED(CONFIG_I2C_SMBUS) int i2c_setup_smbus_alert(struct i2c_adapter *adapter) { + struct device *parent = adapter->dev.parent; int irq; - irq = device_property_match_string(adapter->dev.parent, "interrupt-names", - "smbus_alert"); + /* Adapter instantiated without parent, skip the SMBus alert setup */ + if (!parent) + return 0; + + irq = device_property_match_string(parent, "interrupt-names", "smbus_alert"); if (irq == -EINVAL || irq == -ENODATA) return 0; else if (irq < 0) -- 2.7.4