# These settings are specific to hardening the kernel itself from attack # from userspace, rather than protecting userspace from other malicious # userspace things. # # # When an attacker is trying to exploit the local kernel, it is often # helpful to be able to examine where in memory the kernel, modules, # and data structures live. As such, kernel addresses should be treated # as sensitive information. # # Many files and interfaces contain these addresses (e.g. /proc/kallsyms, # /proc/modules, etc), and this setting can censor the addresses. A value # of "0" allows all users to see the kernel addresses. A value of "1" # limits visibility to the root user, and "2" blocks even the root user. kernel.kptr_restrict = 1