This patch replaces the old grsecurity kernels with a single NixOS
specific grsecurity kernel. This kernel is intended as a general
purpose kernel, tuned for casual desktop use.
Providing only a single kernel may seem like a regression compared to
offering a multitude of flavors. It is impossible, however, to
effectively test and support that many options. This is amplified by
the reality that very few seem to actually use grsecurity on NixOS,
meaning that bugs go unnoticed for long periods of time, simply because
those code paths end up never being exercised. More generally, it is
hopeless to anticipate imagined needs. It is better to start from a
solid foundation and possibly add more flavours on demand.
While the generic kernel is intended to cover a wide range of use cases,
it cannot cover everything. For some, the configuration will be either
too restrictive or too lenient. In those cases, the recommended
solution is to build a custom kernel --- this is *strongly* recommended
for security sensitive deployments.
Building a custom grsec kernel should be as simple as
```nix
linux_grsec_nixos.override {
extraConfig = ''
GRKERNSEC y
PAX y
# and so on ...
'';
}
```
The generic kernel should be usable both as a KVM guest and host. When
running as a host, the kernel assumes hardware virtualisation support.
Virtualisation systems other than KVM are *unsupported*: users of
non-KVM systems are better served by compiling a custom kernel.
Unlike previous Grsecurity kernels, this configuration disables `/proc`
restrictions in favor of `security.hideProcessInformation`.
Known incompatibilities:
- ZFS: can't load spl and zfs kernel modules; claims incompatibility
with KERNEXEC method `or` and RAP; changing to `bts` does not fix the
problem, which implies we'd have to disable RAP as well for ZFS to
work
- `kexec()`: likely incompatible with KERNEXEC (unverified)
- Xen: likely incompatible with KERNEXEC and UDEREF (unverified)
- Virtualbox: likely incompatible with UDEREF (unverified)
Also revert to using the grsecurity-scrape mirror; relying on upstream
just isn't viable. Lately, updates have been so frequent that a new
version is released before Hydra even gets around to building the
previous one.
From now on, only the testing branch of grsecurity will be supported.
Additionally, use only patches from upstream.
It's impossible to provide meaningful support for grsecurity stable.
First, because building and testing \(m \times n \times z) [1], packages
is infeasible. Second, because stable patches are only available from
upstream for-pay, making us reliant on third-parties for patches. In
addition to creating yet more work for the maintainers, using stable
patches provided by a third-party goes against the wishes of upstream.
nixpkgs provides the tools necessary to build grsecurity kernels for any
version the user chooses, however, provided they pay for, or otherwise
acquire, the patch themselves.
Eventually, we'll want to remove the now obsolete top-level attributes,
but leave them in for now to smoothe migration (they have been removed
from top-level/release.nix, though, because it makes no sense to have
them there).
[1]: where \(m\) is the number of grsecurity flavors, \(n\) is the
number of kernel versions, and z is the size of the `linuxPackages` set
Patch drivers/crypto/qat/qat_common/Makefile so that qat_asym_algs.o
explicitly depends on headers qat_rsaprivkey-asn1.h and qat_rsapubkey-asn1.h
Hopefully fixes#14595
This allows to create overlayfs mounts by unprivileged containers (i.e.
in user and mount namespace). It's super-useful for containers.
The patch is trivial as I understand from the patch description it's
does not have security implications (on top of what user namespaces
already have). And it's enabled in ubuntu long time ago. Here is a proof:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1357025
This provides support for Ubuntu Fan Networking [1].
This includes:
* The fanctl package, and a corresponding NixOS service.
* iproute patches.
* kernel patches.
closes#9188
1: https://wiki.ubuntu.com/FanNetworking
This updates the new stable kernel to 3.14, and the new testing kernel
to 3.15.
This also removes the vserver kernel, since it's probably not nearly as
used.
Signed-off-by: Austin Seipp <aseipp@pobox.com>
AppArmor only requires a few patches to the 3.2 and 3.4 kernels in order
to work properly (with the minor catch grsecurity -stable includes the
3.2 patches.) This adds them to the kernel builds by default, removes
features.apparmor (since it's always true) and makes it the default MAC
system.
Signed-off-by: Austin Seipp <aseipp@pobox.com>
kernels:
- longterm: 3.4.87 -> 3.4.88
- longterm: 3.10.37 -> 3.10.38
- stable: 3.13.10 -> 3.13.11
- stable: 3.14.1 -> 3.14.2
grsecurity:
- test: 3.0-3.14.1-201404241722 -> 3.0-3.14.2-201404270907
NOTE: technically the 3.13 stable kernel is now EOL. However, it will
become the long-term grsecurity stable kernel, and will have ongoing
support from Canonical.
Signed-off-by: Austin Seipp <aseipp@pobox.com>
This module implements a significant refactoring in grsecurity
configuration for NixOS, making it far more usable by default and much
easier to configure.
- New security.grsecurity NixOS attributes.
- All grsec kernels supported
- Allows default 'auto' grsec configuration, or custom config
- Supports custom kernel options through kernelExtraConfig
- Defaults to high-security - user must choose kernel, server/desktop
mode, and any virtualisation software. That's all.
- kptr_restrict is fixed under grsecurity (it's unwriteable)
- grsecurity patch creation is now significantly abstracted
- only need revision, version, and SHA1
- kernel version requirements are asserted for sanity
- built kernels can have the uname specify the exact grsec version
for development or bug reports. Off by default (requires
`security.grsecurity.config.verboseVersion = true;`)
- grsecurity sysctl support
- By default, disabled.
- For people who enable it, NixOS deploys a 'grsec-lock' systemd
service which runs at startup. You are expected to configure sysctl
through NixOS like you regularly would, which will occur before the
service is started. As a result, changing sysctl settings requires
a reboot.
- New default group: 'grsecurity'
- Root is a member by default
- GRKERNSEC_PROC_GID is implicitly set to the 'grsecurity' GID,
making it possible to easily add users to this group for /proc
access
- AppArmor is now automatically enabled where it wasn't before, despite
implying features.apparmor = true
The most trivial example of enabling grsecurity in your kernel is by
specifying:
security.grsecurity.enable = true;
security.grsecurity.testing = true; # testing 3.13 kernel
security.grsecurity.config.system = "desktop"; # or "server"
This specifies absolutely no virtualisation support. In general, you
probably at least want KVM host support, which is a little more work.
So:
security.grsecurity.enable = true;
security.grsecurity.stable = true; # enable stable 3.2 kernel
security.grsecurity.config = {
system = "server";
priority = "security";
virtualisationConfig = "host";
virtualisationSoftware = "kvm";
hardwareVirtualisation = true;
}
This module has primarily been tested on Hetzner EX40 & VQ7 servers
using NixOps.
Signed-off-by: Austin Seipp <aseipp@pobox.com>
