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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-20 08:15:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-20 08:15:23 -0700 |
| commit | bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 (patch) | |
| tree | 0446500af9a76d4e8b2a72a0a41391ceede73a10 /Documentation/admin-guide/LSM/LoadPin.rst | |
| download | linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.tar.gz linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.zip | |
Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted
Pull futex fix from Ingo Molnar:
- Also allocate a default private futex hash on vfork() as well, to
avoid races with (private) futex waiters (Peter Zijlstra)
* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Also allocate private hash on vfork()
Diffstat (limited to 'Documentation/admin-guide/LSM/LoadPin.rst')
| -rw-r--r-- | Documentation/admin-guide/LSM/LoadPin.rst | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/Documentation/admin-guide/LSM/LoadPin.rst b/Documentation/admin-guide/LSM/LoadPin.rst new file mode 100644 index 000000000..dd3ca68b5 --- /dev/null +++ b/Documentation/admin-guide/LSM/LoadPin.rst @@ -0,0 +1,31 @@ +======= +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.enforce``". By default, it is enabled, but can be disabled at +boot ("``loadpin.enforce=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.) + +It's also possible to exclude specific file types from LoadPin using kernel +command line option "``loadpin.exclude``". By default, all files are +included, but they can be excluded using kernel command line option such +as "``loadpin.exclude=kernel-module,kexec-image``". This allows to use +different mechanisms such as ``CONFIG_MODULE_SIG`` and +``CONFIG_KEXEC_VERIFY_SIG`` to verify kernel module and kernel image while +still use LoadPin to protect the integrity of other files kernel loads. The +full list of valid file types can be found in ``kernel_read_file_str`` +defined in ``include/linux/kernel_read_file.h``. |
