From 0aef44e84ad16cd87a88df78773fd81ecca34f11 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Peter=20H=C3=BCwe?= Date: Fri, 12 Sep 2014 21:09:47 +0200 Subject: [PATCH] i2c: acpi: Fix NULL Pointer dereference 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 Acked-by: Mika Westerberg Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index b696ac7e6d86..ccfbbab82a15 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -371,10 +371,15 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command, static 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; @@ -407,10 +412,15 @@ static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter) static 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; -- 2.20.1