i2c: smbus: Check for parent device before dereference

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: a263a84088 ("i2c: smbus: Use device_*() functions instead of of_*()")
Reported-by: syzbot+0591ccf54ee05344e4eb@syzkaller.appspotmail.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Andy Shevchenko 2022-02-04 17:59:20 +02:00 committed by Wolfram Sang
parent 017b32e6da
commit 8302532f47

View File

@ -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)