Based on kernel version 6.11
. Page generated on 2024-09-24 08:21 EST
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 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``. |