1# 2# Security configuration 3# 4 5menu "Security options" 6 7config KEYS 8 bool "Enable access key retention support" 9 help 10 This option provides support for retaining authentication tokens and 11 access keys in the kernel. 12 13 It also includes provision of methods by which such keys might be 14 associated with a process so that network filesystems, encryption 15 support and the like can find them. 16 17 Furthermore, a special type of key is available that acts as keyring: 18 a searchable sequence of keys. Each process is equipped with access 19 to five standard keyrings: UID-specific, GID-specific, session, 20 process and thread. 21 22 If you are unsure as to whether this is required, answer N. 23 24config KEYS_DEBUG_PROC_KEYS 25 bool "Enable the /proc/keys file by which keys may be viewed" 26 depends on KEYS 27 help 28 This option turns on support for the /proc/keys file - through which 29 can be listed all the keys on the system that are viewable by the 30 reading process. 31 32 The only keys included in the list are those that grant View 33 permission to the reading process whether or not it possesses them. 34 Note that LSM security checks are still performed, and may further 35 filter out keys that the current process is not authorised to view. 36 37 Only key attributes are listed here; key payloads are not included in 38 the resulting table. 39 40 If you are unsure as to whether this is required, answer N. 41 42config SECURITY 43 bool "Enable different security models" 44 depends on SYSFS 45 help 46 This allows you to choose different security modules to be 47 configured into your kernel. 48 49 If this option is not selected, the default Linux security 50 model will be used. 51 52 If you are unsure how to answer this question, answer N. 53 54config SECURITYFS 55 bool "Enable the securityfs filesystem" 56 help 57 This will build the securityfs filesystem. It is currently used by 58 the TPM bios character driver. It is not used by SELinux or SMACK. 59 60 If you are unsure how to answer this question, answer N. 61 62config SECURITY_NETWORK 63 bool "Socket and Networking Security Hooks" 64 depends on SECURITY 65 help 66 This enables the socket and networking security hooks. 67 If enabled, a security module can use these hooks to 68 implement socket and networking access controls. 69 If you are unsure how to answer this question, answer N. 70 71config SECURITY_NETWORK_XFRM 72 bool "XFRM (IPSec) Networking Security Hooks" 73 depends on XFRM && SECURITY_NETWORK 74 help 75 This enables the XFRM (IPSec) networking security hooks. 76 If enabled, a security module can use these hooks to 77 implement per-packet access controls based on labels 78 derived from IPSec policy. Non-IPSec communications are 79 designated as unlabelled, and only sockets authorized 80 to communicate unlabelled data can send without using 81 IPSec. 82 If you are unsure how to answer this question, answer N. 83 84config SECURITY_FILE_CAPABILITIES 85 bool "File POSIX Capabilities" 86 default n 87 help 88 This enables filesystem capabilities, allowing you to give 89 binaries a subset of root's powers without using setuid 0. 90 91 If in doubt, answer N. 92 93config SECURITY_ROOTPLUG 94 bool "Root Plug Support" 95 depends on USB=y && SECURITY 96 help 97 This is a sample LSM module that should only be used as such. 98 It prevents any programs running with egid == 0 if a specific 99 USB device is not present in the system. 100 101 See <http://www.linuxjournal.com/article.php?sid=6279> for 102 more information about this module. 103 104 If you are unsure how to answer this question, answer N. 105 106config SECURITY_DEFAULT_MMAP_MIN_ADDR 107 int "Low address space to protect from user allocation" 108 depends on SECURITY 109 default 0 110 help 111 This is the portion of low virtual memory which should be protected 112 from userspace allocation. Keeping a user from writing to low pages 113 can help reduce the impact of kernel NULL pointer bugs. 114 115 For most ia64, ppc64 and x86 users with lots of address space 116 a value of 65536 is reasonable and should cause no problems. 117 On arm and other archs it should not be higher than 32768. 118 Programs which use vm86 functionality would either need additional 119 permissions from either the LSM or the capabilities module or have 120 this protection disabled. 121 122 This value can be changed after boot using the 123 /proc/sys/vm/mmap_min_addr tunable. 124 125 126source security/selinux/Kconfig 127source security/smack/Kconfig 128 129endmenu 130 131