linux/security/loadpin/Kconfig

# SPDX-License-Identifier: GPL-2.0-only
config SECURITY_LOADPIN
	bool "Pin load of kernel files (modules, fw, etc) to one filesystem"
	depends on SECURITY && BLOCK
	help
	  Any files read through the kernel file reading interface
	  (kernel modules, firmware, kexec images, security policy)
	  can be pinned to the first filesystem used for loading. When
	  enabled, any files that come from other filesystems will be
	  rejected. This is best used on systems without an initrd that
	  have a root filesystem backed by a read-only device such as
	  dm-verity or a CDROM.

config SECURITY_LOADPIN_ENFORCE
	bool "Enforce LoadPin at boot"
	depends on SECURITY_LOADPIN
	help
	  If selected, LoadPin will enforce pinning at boot. If not
	  selected, it can be enabled at boot with the kernel parameter
	  "loadpin.enforce=1".

config SECURITY_LOADPIN_VERITY
	bool "Allow reading files from certain other filesystems that use dm-verity"
	depends on SECURITY_LOADPIN && DM_VERITY=y && SECURITYFS
	help
	  If selected LoadPin can allow reading files from filesystems
	  that use dm-verity. LoadPin maintains a list of verity root
	  digests it considers trusted. A verity backed filesystem is
	  considered trusted if its root digest is found in the list
	  of trusted digests.

	  The list of trusted verity can be populated through an ioctl
	  on the LoadPin securityfs entry 'dm-verity'. The ioctl
	  expects a file descriptor of a file with verity digests as
	  parameter. The file must be located on the pinned root and
	  start with the line:

	  # LOADPIN_TRUSTED_VERITY_ROOT_DIGESTS

	  This is followed by the verity digests, with one digest per
	  line.