mirror of
https://github.com/torvalds/linux.git
synced 2024-12-15 07:33:56 +00:00
9b091556a0
This LSM enforces that kernel-loaded files (modules, firmware, etc) must all come 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. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
18 lines
986 B
Plaintext
18 lines
986 B
Plaintext
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.)
|