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Diffstat (limited to 'Documentation/admin-guide/LSM/LoadPin.rst')
| -rw-r--r-- | Documentation/admin-guide/LSM/LoadPin.rst | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/Documentation/admin-guide/LSM/LoadPin.rst b/Documentation/admin-guide/LSM/LoadPin.rst new file mode 100644 index 000000000000..32070762d24c --- /dev/null +++ b/Documentation/admin-guide/LSM/LoadPin.rst @@ -0,0 +1,21 @@ +======= +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.) |