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;
--
1.8.5.5
--
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