Hi Wolfram, Do you want me to take care of this or are you going to handle it? It has been ACKed by Mika already: https://patchwork.kernel.org/patch/4897751/ Rafael On Friday, September 12, 2014 09:09:47 PM Peter Huewe wrote: > If adapter->dev.parent == NULL there is a NULL pointer dereference in > acpi_i2c_install_space_handler and acpi_i2c_remove_space_handler. > > This is present since introduction of this code: > 366047515c6e "i2c: rework kernel config I2C_ACPI" or even > da3c6647ee08 "I2C/ACPI: Clean up I2C ACPI code and Add CONFIG_I2C_ACPI" > > The adapter->dev.parent == NULL case is valid for the i2c_stub, > so loading i2c_stub with ACPI_I2C_OPREGION enabled results in an oops. > This is also valid at least for i2c_tiny_usb and i2c_robotfuzz_osif. > > Fix by checking whether it is null before calling ACPI_HANDLE. > > Signed-off-by: Peter Huewe <peterhuewe@xxxxxx> > --- > drivers/i2c/i2c-acpi.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/i2c-acpi.c b/drivers/i2c/i2c-acpi.c > index 0dbc18c..c456b17 100644 > --- a/drivers/i2c/i2c-acpi.c > +++ b/drivers/i2c/i2c-acpi.c > @@ -308,10 +308,15 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command, > > int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) > { > - acpi_handle handle = ACPI_HANDLE(adapter->dev.parent); > + acpi_handle handle; > struct acpi_i2c_handler_data *data; > acpi_status status; > > + if (!adapter->dev.parent) > + return -ENODEV; > + > + handle = ACPI_HANDLE(adapter->dev.parent); > + > if (!handle) > return -ENODEV; > > @@ -344,10 +349,15 @@ int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) > > void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter) > { > - acpi_handle handle = ACPI_HANDLE(adapter->dev.parent); > + acpi_handle handle; > struct acpi_i2c_handler_data *data; > acpi_status status; > > + if (!adapter->dev.parent) > + return; > + > + handle = ACPI_HANDLE(adapter->dev.parent); > + > if (!handle) > return; > > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
