Commit graph

10 commits

Author SHA1 Message Date
Izorkin e21e5a9483 nixos/security/misc: add option unprivilegedUsernsClone 2020-08-25 14:18:24 +03:00
Pierre Bourdon 67b7e70865
nixos/hardened: make pti=on overridable
Introduces a new security.forcePageTableIsolation option (default false
on !hardened, true on hardened) that forces pti=on.
2019-07-30 02:24:56 +02:00
Marek Mahut e72f25673d Renaming security.virtualization.flushL1DataCache to virtualisation
Fixes #65044
2019-07-19 15:49:37 +02:00
Eelco Dolstra de9e238469
FIx some malformed XML in option descriptions
E.g. these were using "<para>" at the *end* of a description. The real
WTF is that this is possible at all...
2019-05-13 09:15:17 +02:00
Joachim Fasting b33da46a8e
nixos/hardened: split description of allowUserNamespaces into paras 2019-04-21 13:11:25 +02:00
Joachim Fasting ea4f371627
nixos/security/misc: expose SMT control option
For the hardened profile disable symmetric multi threading.  There seems to be
no *proven* method of exploiting cache sharing between threads on the same CPU
core, so this may be considered quite paranoid, considering the perf cost.
SMT can be controlled at runtime, however.  This is in keeping with OpenBSD
defaults.

TODO: since SMT is left to be controlled at runtime, changing the option
definition should take effect on system activation.  Write to
/sys/devices/system/cpu/smt/control
2018-12-27 15:00:49 +01:00
Joachim Fasting e9761fa327
nixos/security/misc: expose l1tf mitigation option
For the hardened profile enable flushing whenever the hypervisor enters the
guest, but otherwise leave at kernel default (conditional flushing as of
writing).
2018-12-27 15:00:48 +01:00
Joachim Fasting 84fb8820db
nixos/security/misc: factor out protectKernelImage
Introduces the option security.protectKernelImage that is intended to control
various mitigations to protect the integrity of the running kernel
image (i.e., prevent replacing it without rebooting).

This makes sense as a dedicated module as it is otherwise somewhat difficult
to override for hardened profile users who want e.g., hibernation to work.
2018-12-27 15:00:47 +01:00
Joachim Fasting 9db84f6fcd
nixos/security/misc: use mkMerge for easier extension 2018-12-27 15:00:46 +01:00
Joachim Fasting f4ea22e5de
nixos/security/misc: init
A module for security options that are too small to warrant their own module.

The impetus for adding this module is to make it more convenient to override
the behavior of the hardened profile wrt user namespaces.
Without a dedicated option for user namespaces, the user needs to
1) know which sysctl knob controls userns
2) know how large a value the sysctl knob needs to allow e.g.,
   Nix sandbox builds to work

In the future, other mitigations currently enabled by the hardened profile may
be promoted to options in this module.
2018-10-15 23:11:37 +02:00