Adds an option `security.lockKernelModules` that, when enabled, disables
kernel module loading once the system reaches its normal operating state.
The rationale for this over simply setting the sysctl knob is to allow
some legitmate kernel module loading to occur; the naive solution breaks
too much to be useful.
The benefit to the user is to help ensure the integrity of the kernel
runtime: only code loaded as part of normal system initialization will be
available in the kernel for the duration of the boot session. This helps
prevent injection of malicious code or unexpected loading of legitimate
but normally unused modules that have exploitable bugs (e.g., DCCP use
after free CVE-2017-6074, n_hldc CVE-2017-2636, XFRM framework
CVE-2017-7184, L2TPv3 CVE-2016-10200).
From an aestethic point of view, enabling this option helps make the
configuration more "declarative".
Closes https://github.com/NixOS/nixpkgs/pull/24681
Use a solid black background when no background image (via
~/.background-image) is provided. In my case this fixes the really
strange behaviour when i3 without a desktop manager starts with the SDDM
login screen as background image.
This eliminates a theoretical risk of ASLR bypass due to the fixed address
mapping used by the legacy vsyscall mechanism. Modern glibc use vdso(7)
instead so there is no loss of functionality, but some programs may fail
to run in this configuration. Programs that fail to run because vsyscall
has been disabled will be logged to dmesg.
For background on virtual syscalls see https://lwn.net/Articles/446528/
Closes https://github.com/NixOS/nixpkgs/pull/25289
The xsession script was called with inconsistent (depending on the
display managers) and wrong parameters. The main reason for this where
the spaces the parameter syntax. In order to fix this the old syntax:
$1 = '<desktop-manager> + <window-manager>'
Will be replaced with a new syntax:
$1 = "<desktop-manager>+<window-manager>"
This assumes that neither "<desktop-manager>" nor "<window-manager>"
contain the "+" character but this shouldn't be a problem.
This patch also fixes the quoting by using double quotes (") instead of
single quotes (') [0].
Last but not least this'll add some comments for the better
understanding of the script.
[0]: https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s06.html
Upstream has decided to make -testing patches private, effectively ceasing
free support for grsecurity/PaX [1]. Consequently, we can no longer
responsibly support grsecurity on NixOS.
This patch turns the kernel and patch expressions into build errors and
adds a warning to the manual, but retains most of the infrastructure, in
an effort to make the transition smoother. For 17.09 all of it should
probably be pruned.
[1]: https://grsecurity.net/passing_the_baton.php
