22 lines
1.0 KiB
ReStructuredText
22 lines
1.0 KiB
ReStructuredText
|
=======
|
||
|
|
LoadPin
|
||
|
|
=======
|
||
|
|
|
||
|
|
LoadPin is a Linux Security Module that ensures all kernel-loaded files
|
||
|
|
(modules, firmware, etc) all originate from the same filesystem, with
|
||
|
|
the expectation that such a filesystem is backed by a read-only device
|
||
|
|
such as dm-verity or CDROM. This allows systems that have a verified
|
||
|
|
and/or unchangeable filesystem to enforce module and firmware loading
|
||
|
|
restrictions without needing to sign the files individually.
|
||
|
|
|
||
|
|
The LSM is selectable at build-time with ``CONFIG_SECURITY_LOADPIN``, and
|
||
|
|
can be controlled at boot-time with the kernel command line option
|
||
|
|
"``loadpin.enabled``". By default, it is enabled, but can be disabled at
|
||
|
|
boot ("``loadpin.enabled=0``").
|
||
|
|
|
||
|
|
LoadPin starts pinning when it sees the first file loaded. If the
|
||
|
|
block device backing the filesystem is not read-only, a sysctl is
|
||
|
|
created to toggle pinning: ``/proc/sys/kernel/loadpin/enabled``. (Having
|
||
|
|
a mutable filesystem means pinning is mutable too, but having the
|
||
|
|
sysctl allows for easy testing on systems with a mutable filesystem.)
|