Messages in this thread Patch in this message | | | From | Peter Huewe <> | Subject | [PATCH] [REGRESSION] i2c-acpi: Fix NULL Pointer dereference | Date | Fri, 12 Sep 2014 21:09:47 +0200 |
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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@gmx.de> --- 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; -- 1.8.5.5
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