linux-hardened sets kernel.unprivileged_userns_clone=0 by default; see
anthraxx/linux-hardened@104f44058f.
This allows the Nix sandbox to function while reducing the attack
surface posed by user namespaces, which allow unprivileged code to
exercise lots of root-only code paths and have lead to privilege
escalation vulnerabilities in the past.
We can safely leave user namespaces on for privileged users, as root
already has root privileges, but if you're not running builds on your
machine and really want to minimize the kernel attack surface then you
can set security.allowUserNamespaces to false.
Note that Chrome's sandbox requires either unprivileged CLONE_NEWUSER or
setuid, and Firefox's silently reduces the security level if it isn't
allowed (see about:support), so desktop users may want to set:
boot.kernel.sysctl."kernel.unprivileged_userns_clone" = true;
As far as I can tell, this has never defaulted to on upstream, and our
common kernel configuration doesn't turn it on, so the attack surface
reduction here is somewhat homeopathic.
This is an updated version of the former upstream,
https://github.com/AndroidHardeningArchive/linux-hardened, and provides
a minimal set of additional hardening patches on top of upstream.
The patch already incorporates many of our hardened profile defaults,
and releases are timely (Linux 5.5.15 and 5.6.2 were released on
2020-04-02; linux-hardened patches for them came out on 2020-04-03 and
2020-04-04 respectively).
* nixos/k3s: simplify config expression
* nixos/k3s: add config assertions and trim unneeded bits
* nixos/k3s: add a test that k3s works; minor module improvements
This is a single-node test. Eventually we should also have a multi-node
test to verify the agent bit works, but that one's more involved.
* nixos/k3s: add option description
* nixos/k3s: add defaults for token/serveraddr
Now that the assertion enforces their presence, we dont' need to use the typesystem for it.
* nixos/k3s: remove unneeded sudo in test
* nixos/k3s: add to test list
The patch phase runs after the build phase. Which means than when
using an override to override both 'conf' and 'patches' to provide
a custom config file and apply some patches, it doesn't work:
- first the patches applied (optionally changing config.def.h)
- then preBuild is run which overrides config.def.h with the user
supplied one (effectively cancelling previously applied patches)
By copying the config file in the prePatch phase instead, changes
are kept and applied in order.
After the recent rewrite, enabled extensions are passed to php programs
through an extra ini file by a wrapper. Since httpd uses shared module
instead of program, the wrapper did not affect it and no extensions
other than built-ins were loaded.
To fix this, we are passing the extension config another way – by adding it
to the service's generated config.
For now we are hardcoding the path to the ini file. It would be nice to add
the path to the passthru and use that once the PHP expression settles down.
