Security in Linux Kernel - Part 2
In the previous part of this series, we saw role of LSMs in kernel security. As mentioned earlier, there are eight LSMs available today in the modern Linux kernel. In this part, let's have a look at different main stream LSMs. SMACK Simplified Mandatory Access Control Kernel ( SMACK ) is designed primarily for embedded linux systems with an intention to make it easier for administrators. This was the second LSM (after SELinux) to be accepted in the linux kernel. It appeared in the 2.6.25 kernel release. This is an attribute (label) based simple LSM, and is the default for Linux implementations tuned for Automotive industry. Yama Yama collects system-wide DAC security restrictions that are not handled by the core kernel itself. It offers control over scope of ptrace() system call to control ptrace attachment by processes. Build time configuration option CONFIG_SECURITY_YAMA and runtime option through sysctls can be used to enable this LSM. The ptrace restrictions can be controll...