 7e70cb4978
			
		
	
	
	7e70cb4978
	
	
	
		
			
			Define a new kernel key-type called 'encrypted'. Encrypted keys are kernel generated random numbers, which are encrypted/decrypted with a 'trusted' symmetric key. Encrypted keys are created/encrypted/decrypted in the kernel. Userspace only ever sees/stores encrypted blobs. Changelog: - bug fix: replaced master-key rcu based locking with semaphore (reported by David Howells) - Removed memset of crypto_shash_digest() digest output - Replaced verification of 'key-type:key-desc' using strcspn(), with one based on string constants. - Moved documentation to Documentation/keys-trusted-encrypted.txt - Replace hash with shash (based on comments by David Howells) - Make lengths/counts size_t where possible (based on comments by David Howells) Could not convert most lengths, as crypto expects 'unsigned int' (size_t: on 32 bit is defined as unsigned int, but on 64 bit is unsigned long) - Add 'const' where possible (based on comments by David Howells) - allocate derived_buf dynamically to support arbitrary length master key (fixed by Roberto Sassu) - wait until late_initcall for crypto libraries to be registered - cleanup security/Kconfig - Add missing 'update' keyword (reported/fixed by Roberto Sassu) - Free epayload on failure to create key (reported/fixed by Roberto Sassu) - Increase the data size limit (requested by Roberto Sassu) - Crypto return codes are always 0 on success and negative on failure, remove unnecessary tests. - Replaced kzalloc() with kmalloc() Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: David Safford <safford@watson.ibm.com> Reviewed-by: Roberto Sassu <roberto.sassu@polito.it> Signed-off-by: James Morris <jmorris@namei.org>
		
			
				
	
	
		
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			228 lines
		
	
	
	
		
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| #
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| # Security configuration
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| #
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| 
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| menu "Security options"
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| 
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| config KEYS
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| 	bool "Enable access key retention support"
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| 	help
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| 	  This option provides support for retaining authentication tokens and
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| 	  access keys in the kernel.
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| 
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| 	  It also includes provision of methods by which such keys might be
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| 	  associated with a process so that network filesystems, encryption
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| 	  support and the like can find them.
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| 
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| 	  Furthermore, a special type of key is available that acts as keyring:
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| 	  a searchable sequence of keys. Each process is equipped with access
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| 	  to five standard keyrings: UID-specific, GID-specific, session,
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| 	  process and thread.
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| 
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| 	  If you are unsure as to whether this is required, answer N.
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| 
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| config TRUSTED_KEYS
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| 	tristate "TRUSTED KEYS"
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| 	depends on KEYS && TCG_TPM
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| 	select CRYPTO
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| 	select CRYPTO_HMAC
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| 	select CRYPTO_SHA1
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| 	help
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| 	  This option provides support for creating, sealing, and unsealing
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| 	  keys in the kernel. Trusted keys are random number symmetric keys,
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| 	  generated and RSA-sealed by the TPM. The TPM only unseals the keys,
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| 	  if the boot PCRs and other criteria match.  Userspace will only ever
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| 	  see encrypted blobs.
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| 
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| 	  If you are unsure as to whether this is required, answer N.
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| 
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| config ENCRYPTED_KEYS
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| 	tristate "ENCRYPTED KEYS"
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| 	depends on KEYS && TRUSTED_KEYS
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| 	select CRYPTO_AES
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| 	select CRYPTO_CBC
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| 	select CRYPTO_SHA256
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| 	select CRYPTO_RNG
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| 	help
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| 	  This option provides support for create/encrypting/decrypting keys
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| 	  in the kernel.  Encrypted keys are kernel generated random numbers,
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| 	  which are encrypted/decrypted with a 'master' symmetric key. The
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| 	  'master' key can be either a trusted-key or user-key type.
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| 	  Userspace only ever sees/stores encrypted blobs.
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| 
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| 	  If you are unsure as to whether this is required, answer N.
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| 
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| config KEYS_DEBUG_PROC_KEYS
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| 	bool "Enable the /proc/keys file by which keys may be viewed"
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| 	depends on KEYS
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| 	help
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| 	  This option turns on support for the /proc/keys file - through which
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| 	  can be listed all the keys on the system that are viewable by the
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| 	  reading process.
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| 
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| 	  The only keys included in the list are those that grant View
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| 	  permission to the reading process whether or not it possesses them.
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| 	  Note that LSM security checks are still performed, and may further
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| 	  filter out keys that the current process is not authorised to view.
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| 
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| 	  Only key attributes are listed here; key payloads are not included in
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| 	  the resulting table.
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| 
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| 	  If you are unsure as to whether this is required, answer N.
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| 
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| config SECURITY_DMESG_RESTRICT
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| 	bool "Restrict unprivileged access to the kernel syslog"
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| 	default n
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| 	help
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| 	  This enforces restrictions on unprivileged users reading the kernel
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| 	  syslog via dmesg(8).
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| 
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| 	  If this option is not selected, no restrictions will be enforced
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| 	  unless the dmesg_restrict sysctl is explicitly set to (1).
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| 
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| 	  If you are unsure how to answer this question, answer N.
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| 
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| config SECURITY
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| 	bool "Enable different security models"
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| 	depends on SYSFS
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| 	help
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| 	  This allows you to choose different security modules to be
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| 	  configured into your kernel.
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| 
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| 	  If this option is not selected, the default Linux security
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| 	  model will be used.
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| 
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| 	  If you are unsure how to answer this question, answer N.
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| 
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| config SECURITYFS
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| 	bool "Enable the securityfs filesystem"
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| 	help
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| 	  This will build the securityfs filesystem.  It is currently used by
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| 	  the TPM bios character driver and IMA, an integrity provider.  It is
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| 	  not used by SELinux or SMACK.
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| 
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| 	  If you are unsure how to answer this question, answer N.
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| 
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| config SECURITY_NETWORK
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| 	bool "Socket and Networking Security Hooks"
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| 	depends on SECURITY
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| 	help
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| 	  This enables the socket and networking security hooks.
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| 	  If enabled, a security module can use these hooks to
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| 	  implement socket and networking access controls.
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| 	  If you are unsure how to answer this question, answer N.
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| 
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| config SECURITY_NETWORK_XFRM
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| 	bool "XFRM (IPSec) Networking Security Hooks"
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| 	depends on XFRM && SECURITY_NETWORK
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| 	help
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| 	  This enables the XFRM (IPSec) networking security hooks.
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| 	  If enabled, a security module can use these hooks to
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| 	  implement per-packet access controls based on labels
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| 	  derived from IPSec policy.  Non-IPSec communications are
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| 	  designated as unlabelled, and only sockets authorized
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| 	  to communicate unlabelled data can send without using
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| 	  IPSec.
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| 	  If you are unsure how to answer this question, answer N.
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| 
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| config SECURITY_PATH
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| 	bool "Security hooks for pathname based access control"
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| 	depends on SECURITY
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| 	help
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| 	  This enables the security hooks for pathname based access control.
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| 	  If enabled, a security module can use these hooks to
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| 	  implement pathname based access controls.
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| 	  If you are unsure how to answer this question, answer N.
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| 
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| config INTEL_TXT
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| 	bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
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| 	depends on HAVE_INTEL_TXT
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| 	help
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| 	  This option enables support for booting the kernel with the
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| 	  Trusted Boot (tboot) module. This will utilize
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| 	  Intel(R) Trusted Execution Technology to perform a measured launch
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| 	  of the kernel. If the system does not support Intel(R) TXT, this
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| 	  will have no effect.
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| 
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| 	  Intel TXT will provide higher assurance of system configuration and
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| 	  initial state as well as data reset protection.  This is used to
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| 	  create a robust initial kernel measurement and verification, which
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| 	  helps to ensure that kernel security mechanisms are functioning
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| 	  correctly. This level of protection requires a root of trust outside
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| 	  of the kernel itself.
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| 
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| 	  Intel TXT also helps solve real end user concerns about having
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| 	  confidence that their hardware is running the VMM or kernel that
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| 	  it was configured with, especially since they may be responsible for
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| 	  providing such assurances to VMs and services running on it.
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| 
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| 	  See <http://www.intel.com/technology/security/> for more information
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| 	  about Intel(R) TXT.
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| 	  See <http://tboot.sourceforge.net> for more information about tboot.
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| 	  See Documentation/intel_txt.txt for a description of how to enable
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| 	  Intel TXT support in a kernel boot.
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| 
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| 	  If you are unsure as to whether this is required, answer N.
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| 
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| config LSM_MMAP_MIN_ADDR
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| 	int "Low address space for LSM to protect from user allocation"
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| 	depends on SECURITY && SECURITY_SELINUX
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| 	default 65536
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| 	help
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| 	  This is the portion of low virtual memory which should be protected
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| 	  from userspace allocation.  Keeping a user from writing to low pages
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| 	  can help reduce the impact of kernel NULL pointer bugs.
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| 
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| 	  For most ia64, ppc64 and x86 users with lots of address space
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| 	  a value of 65536 is reasonable and should cause no problems.
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| 	  On arm and other archs it should not be higher than 32768.
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| 	  Programs which use vm86 functionality or have some need to map
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| 	  this low address space will need the permission specific to the
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| 	  systems running LSM.
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| 
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| source security/selinux/Kconfig
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| source security/smack/Kconfig
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| source security/tomoyo/Kconfig
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| source security/apparmor/Kconfig
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| 
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| source security/integrity/ima/Kconfig
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| 
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| choice
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| 	prompt "Default security module"
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| 	default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX
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| 	default DEFAULT_SECURITY_SMACK if SECURITY_SMACK
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| 	default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO
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| 	default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR
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| 	default DEFAULT_SECURITY_DAC
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| 
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| 	help
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| 	  Select the security module that will be used by default if the
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| 	  kernel parameter security= is not specified.
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| 
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| 	config DEFAULT_SECURITY_SELINUX
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| 		bool "SELinux" if SECURITY_SELINUX=y
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| 
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| 	config DEFAULT_SECURITY_SMACK
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| 		bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y
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| 
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| 	config DEFAULT_SECURITY_TOMOYO
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| 		bool "TOMOYO" if SECURITY_TOMOYO=y
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| 
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| 	config DEFAULT_SECURITY_APPARMOR
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| 		bool "AppArmor" if SECURITY_APPARMOR=y
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| 
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| 	config DEFAULT_SECURITY_DAC
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| 		bool "Unix Discretionary Access Controls"
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| 
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| endchoice
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| 
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| config DEFAULT_SECURITY
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| 	string
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| 	default "selinux" if DEFAULT_SECURITY_SELINUX
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| 	default "smack" if DEFAULT_SECURITY_SMACK
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| 	default "tomoyo" if DEFAULT_SECURITY_TOMOYO
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| 	default "apparmor" if DEFAULT_SECURITY_APPARMOR
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| 	default "" if DEFAULT_SECURITY_DAC
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| 
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| endmenu
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| 
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