1# 2# Security configuration 3# 4 5menu "Security options" 6 7source security/keys/Kconfig 8 9config SECURITY_DMESG_RESTRICT 10 bool "Restrict unprivileged access to the kernel syslog" 11 default n 12 help 13 This enforces restrictions on unprivileged users reading the kernel 14 syslog via dmesg(8). 15 16 If this option is not selected, no restrictions will be enforced 17 unless the dmesg_restrict sysctl is explicitly set to (1). 18 19 If you are unsure how to answer this question, answer N. 20 21config SECURITY 22 bool "Enable different security models" 23 depends on SYSFS 24 depends on MULTIUSER 25 help 26 This allows you to choose different security modules to be 27 configured into your kernel. 28 29 If this option is not selected, the default Linux security 30 model will be used. 31 32 If you are unsure how to answer this question, answer N. 33 34config SECURITYFS 35 bool "Enable the securityfs filesystem" 36 help 37 This will build the securityfs filesystem. It is currently used by 38 the TPM bios character driver and IMA, an integrity provider. It is 39 not used by SELinux or SMACK. 40 41 If you are unsure how to answer this question, answer N. 42 43config SECURITY_NETWORK 44 bool "Socket and Networking Security Hooks" 45 depends on SECURITY 46 help 47 This enables the socket and networking security hooks. 48 If enabled, a security module can use these hooks to 49 implement socket and networking access controls. 50 If you are unsure how to answer this question, answer N. 51 52config SECURITY_NETWORK_XFRM 53 bool "XFRM (IPSec) Networking Security Hooks" 54 depends on XFRM && SECURITY_NETWORK 55 help 56 This enables the XFRM (IPSec) networking security hooks. 57 If enabled, a security module can use these hooks to 58 implement per-packet access controls based on labels 59 derived from IPSec policy. Non-IPSec communications are 60 designated as unlabelled, and only sockets authorized 61 to communicate unlabelled data can send without using 62 IPSec. 63 If you are unsure how to answer this question, answer N. 64 65config SECURITY_PATH 66 bool "Security hooks for pathname based access control" 67 depends on SECURITY 68 help 69 This enables the security hooks for pathname based access control. 70 If enabled, a security module can use these hooks to 71 implement pathname based access controls. 72 If you are unsure how to answer this question, answer N. 73 74config INTEL_TXT 75 bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)" 76 depends on HAVE_INTEL_TXT 77 help 78 This option enables support for booting the kernel with the 79 Trusted Boot (tboot) module. This will utilize 80 Intel(R) Trusted Execution Technology to perform a measured launch 81 of the kernel. If the system does not support Intel(R) TXT, this 82 will have no effect. 83 84 Intel TXT will provide higher assurance of system configuration and 85 initial state as well as data reset protection. This is used to 86 create a robust initial kernel measurement and verification, which 87 helps to ensure that kernel security mechanisms are functioning 88 correctly. This level of protection requires a root of trust outside 89 of the kernel itself. 90 91 Intel TXT also helps solve real end user concerns about having 92 confidence that their hardware is running the VMM or kernel that 93 it was configured with, especially since they may be responsible for 94 providing such assurances to VMs and services running on it. 95 96 See <http://www.intel.com/technology/security/> for more information 97 about Intel(R) TXT. 98 See <http://tboot.sourceforge.net> for more information about tboot. 99 See Documentation/intel_txt.txt for a description of how to enable 100 Intel TXT support in a kernel boot. 101 102 If you are unsure as to whether this is required, answer N. 103 104config LSM_MMAP_MIN_ADDR 105 int "Low address space for LSM to protect from user allocation" 106 depends on SECURITY && SECURITY_SELINUX 107 default 32768 if ARM || (ARM64 && COMPAT) 108 default 65536 109 help 110 This is the portion of low virtual memory which should be protected 111 from userspace allocation. Keeping a user from writing to low pages 112 can help reduce the impact of kernel NULL pointer bugs. 113 114 For most ia64, ppc64 and x86 users with lots of address space 115 a value of 65536 is reasonable and should cause no problems. 116 On arm and other archs it should not be higher than 32768. 117 Programs which use vm86 functionality or have some need to map 118 this low address space will need the permission specific to the 119 systems running LSM. 120 121config HAVE_HARDENED_USERCOPY_ALLOCATOR 122 bool 123 help 124 The heap allocator implements __check_heap_object() for 125 validating memory ranges against heap object sizes in 126 support of CONFIG_HARDENED_USERCOPY. 127 128config HARDENED_USERCOPY 129 bool "Harden memory copies between kernel and userspace" 130 depends on HAVE_HARDENED_USERCOPY_ALLOCATOR 131 select BUG 132 help 133 This option checks for obviously wrong memory regions when 134 copying memory to/from the kernel (via copy_to_user() and 135 copy_from_user() functions) by rejecting memory ranges that 136 are larger than the specified heap object, span multiple 137 separately allocates pages, are not on the process stack, 138 or are part of the kernel text. This kills entire classes 139 of heap overflow exploits and similar kernel memory exposures. 140 141config HARDENED_USERCOPY_PAGESPAN 142 bool "Refuse to copy allocations that span multiple pages" 143 depends on HARDENED_USERCOPY 144 depends on EXPERT 145 help 146 When a multi-page allocation is done without __GFP_COMP, 147 hardened usercopy will reject attempts to copy it. There are, 148 however, several cases of this in the kernel that have not all 149 been removed. This config is intended to be used only while 150 trying to find such users. 151 152config STATIC_USERMODEHELPER 153 bool "Force all usermode helper calls through a single binary" 154 help 155 By default, the kernel can call many different userspace 156 binary programs through the "usermode helper" kernel 157 interface. Some of these binaries are statically defined 158 either in the kernel code itself, or as a kernel configuration 159 option. However, some of these are dynamically created at 160 runtime, or can be modified after the kernel has started up. 161 To provide an additional layer of security, route all of these 162 calls through a single executable that can not have its name 163 changed. 164 165 Note, it is up to this single binary to then call the relevant 166 "real" usermode helper binary, based on the first argument 167 passed to it. If desired, this program can filter and pick 168 and choose what real programs are called. 169 170 If you wish for all usermode helper programs are to be 171 disabled, choose this option and then set 172 STATIC_USERMODEHELPER_PATH to an empty string. 173 174config STATIC_USERMODEHELPER_PATH 175 string "Path to the static usermode helper binary" 176 depends on STATIC_USERMODEHELPER 177 default "/sbin/usermode-helper" 178 help 179 The binary called by the kernel when any usermode helper 180 program is wish to be run. The "real" application's name will 181 be in the first argument passed to this program on the command 182 line. 183 184 If you wish for all usermode helper programs to be disabled, 185 specify an empty string here (i.e. ""). 186 187source security/selinux/Kconfig 188source security/smack/Kconfig 189source security/tomoyo/Kconfig 190source security/apparmor/Kconfig 191source security/loadpin/Kconfig 192source security/yama/Kconfig 193 194source security/integrity/Kconfig 195 196choice 197 prompt "Default security module" 198 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX 199 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK 200 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO 201 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR 202 default DEFAULT_SECURITY_DAC 203 204 help 205 Select the security module that will be used by default if the 206 kernel parameter security= is not specified. 207 208 config DEFAULT_SECURITY_SELINUX 209 bool "SELinux" if SECURITY_SELINUX=y 210 211 config DEFAULT_SECURITY_SMACK 212 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y 213 214 config DEFAULT_SECURITY_TOMOYO 215 bool "TOMOYO" if SECURITY_TOMOYO=y 216 217 config DEFAULT_SECURITY_APPARMOR 218 bool "AppArmor" if SECURITY_APPARMOR=y 219 220 config DEFAULT_SECURITY_DAC 221 bool "Unix Discretionary Access Controls" 222 223endchoice 224 225config DEFAULT_SECURITY 226 string 227 default "selinux" if DEFAULT_SECURITY_SELINUX 228 default "smack" if DEFAULT_SECURITY_SMACK 229 default "tomoyo" if DEFAULT_SECURITY_TOMOYO 230 default "apparmor" if DEFAULT_SECURITY_APPARMOR 231 default "" if DEFAULT_SECURITY_DAC 232 233endmenu 234 235