[Query] Looking for comments on CONFIG_SPI_SPIDEV and CONFIG_I2C_CHARDEV interfaces security

[Prasad Sodagudi]

Hi All,

I am working on an IoT solution and would like to understand security 
impact of these two CONFIG_SPI_SPIDEV and CONFIG_I2C_CHARDEV interfaces 
of Linux. If a driver is developed from userspace for  /dev/spiX.Y or 
/dev/i2c interfaces,  are there any security concerns ?

Userspace driver is to control external SPI slave on board. I heard that 
these interfaces allows access to any of these type of devices on board. 
 How to avoid accessing any of these type of unwanted device access 
from userspace ?  Can Selinux or any mechanism control access to other 
these type of devices from user-space ?

Please share your comments/findings on these two interfaces related to 
security. If community had posted any security related discussions with 
these interfaces, please share details to improve understanding.

-Thanks, Prasad