Re: [gentoo-dev] Vanilla sources

[Michael 'veremitz' Everitt]

On 03/01/20 14:48, Toralf Förster wrote:
> On 1/3/20 3:46 PM, Rich Freeman wrote:
>> If OpenRC contains a vulnerability wouldn't it make more sense to set
>> this as part of OpenRC,
> Indeed.
>
> Furthermore there's a nifty page https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings
> which yields for me to this /etc/sysctl.d/local.conf :
>
>
> #       Restrict potential illegal access via links
> #
> fs.protected_hardlinks = 1
> fs.protected_symlinks = 1
>
> #
> # https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project#CONFIGs
> #
>
> # Try to keep kernel address exposures out of various /proc files (kallsyms, modules, etc).
> kernel.kptr_restrict = 1
>
> # Avoid kernel memory address exposures via dmesg.
> kernel.dmesg_restrict = 1
>
> # Block non-uid-0 profiling (needs distro patch, otherwise this is the same as "= 2")
> kernel.perf_event_paranoid = 3
>
> # Turn off kexec, even if it's built in.
> kernel.kexec_load_disabled = 1
>
> # Avoid non-ancestor ptrace access to running processes and their credentials.
> kernel.yama.ptrace_scope = 1
>
> # Disable User Namespaces, as it opens up a large attack surface to unprivileged users.
> user.max_user_namespaces = 0
>
> # Turn off unprivileged eBPF access.
> kernel.unprivileged_bpf_disabled = 1
>
> # Turn on BPF JIT hardening, if the JIT is enabled.
> net.core.bpf_jit_harden = 2
>
>
FWIW, there is a move to add further hardening options to the
Gentoo-sources kernel - bug 689154, based on the kernsec recommendations.
Further details of proposals, and inspiration, are in the bug.