CONFIG_IKCONFIG_PROC - security implications

[krotuss]

Hi, what are security implications of using "CONFIG_IKCONFIG_PROC=y"? "/proc/config.gz" is world readable (can it be changed?), but for that matter also "/etc/kernels/kernel-config-*". Doesn't exposing kernel config to attacker make it easier to identify potential security vulnerabilities? Or, in reality, it doesn't make much difference?

[Hu]

Permissions for this pseudo-file are hardcoded in the kernel; you would need a kernel patch to change them. See kernel/configs.c.

Yes, you should never give an attacker any information, because knowing anything makes their lives easier. Ideally, you should not let them run any code of their choosing on the system, in which case they will have a much harder time triggering any vulnerabilities.

I expect that in practice most attackers will not bother examining the kernel configuration, and will just blindly attempt any exploits they think might work. They might check your kernel version, or just try everything they know to try.