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 HAVE_ARCH_HARDENED_USERCOPY 129 bool 130 help 131 The architecture supports CONFIG_HARDENED_USERCOPY by 132 calling check_object_size() just before performing the 133 userspace copies in the low level implementation of 134 copy_to_user() and copy_from_user(). 135 136config HARDENED_USERCOPY 137 bool "Harden memory copies between kernel and userspace" 138 depends on HAVE_ARCH_HARDENED_USERCOPY 139 depends on HAVE_HARDENED_USERCOPY_ALLOCATOR 140 select BUG 141 help 142 This option checks for obviously wrong memory regions when 143 copying memory to/from the kernel (via copy_to_user() and 144 copy_from_user() functions) by rejecting memory ranges that 145 are larger than the specified heap object, span multiple 146 separately allocates pages, are not on the process stack, 147 or are part of the kernel text. This kills entire classes 148 of heap overflow exploits and similar kernel memory exposures. 149 150config HARDENED_USERCOPY_PAGESPAN 151 bool "Refuse to copy allocations that span multiple pages" 152 depends on HARDENED_USERCOPY 153 depends on EXPERT 154 help 155 When a multi-page allocation is done without __GFP_COMP, 156 hardened usercopy will reject attempts to copy it. There are, 157 however, several cases of this in the kernel that have not all 158 been removed. This config is intended to be used only while 159 trying to find such users. 160 161config STATIC_USERMODEHELPER 162 bool "Force all usermode helper calls through a single binary" 163 help 164 By default, the kernel can call many different userspace 165 binary programs through the "usermode helper" kernel 166 interface. Some of these binaries are statically defined 167 either in the kernel code itself, or as a kernel configuration 168 option. However, some of these are dynamically created at 169 runtime, or can be modified after the kernel has started up. 170 To provide an additional layer of security, route all of these 171 calls through a single executable that can not have its name 172 changed. 173 174 Note, it is up to this single binary to then call the relevant 175 "real" usermode helper binary, based on the first argument 176 passed to it. If desired, this program can filter and pick 177 and choose what real programs are called. 178 179 If you wish for all usermode helper programs are to be 180 disabled, choose this option and then set 181 STATIC_USERMODEHELPER_PATH to an empty string. 182 183config STATIC_USERMODEHELPER_PATH 184 string "Path to the static usermode helper binary" 185 depends on STATIC_USERMODEHELPER 186 default "/sbin/usermode-helper" 187 help 188 The binary called by the kernel when any usermode helper 189 program is wish to be run. The "real" application's name will 190 be in the first argument passed to this program on the command 191 line. 192 193 If you wish for all usermode helper programs to be disabled, 194 specify an empty string here (i.e. ""). 195 196source security/selinux/Kconfig 197source security/smack/Kconfig 198source security/tomoyo/Kconfig 199source security/apparmor/Kconfig 200source security/loadpin/Kconfig 201source security/yama/Kconfig 202 203source security/integrity/Kconfig 204 205choice 206 prompt "Default security module" 207 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX 208 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK 209 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO 210 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR 211 default DEFAULT_SECURITY_DAC 212 213 help 214 Select the security module that will be used by default if the 215 kernel parameter security= is not specified. 216 217 config DEFAULT_SECURITY_SELINUX 218 bool "SELinux" if SECURITY_SELINUX=y 219 220 config DEFAULT_SECURITY_SMACK 221 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y 222 223 config DEFAULT_SECURITY_TOMOYO 224 bool "TOMOYO" if SECURITY_TOMOYO=y 225 226 config DEFAULT_SECURITY_APPARMOR 227 bool "AppArmor" if SECURITY_APPARMOR=y 228 229 config DEFAULT_SECURITY_DAC 230 bool "Unix Discretionary Access Controls" 231 232endchoice 233 234config DEFAULT_SECURITY 235 string 236 default "selinux" if DEFAULT_SECURITY_SELINUX 237 default "smack" if DEFAULT_SECURITY_SMACK 238 default "tomoyo" if DEFAULT_SECURITY_TOMOYO 239 default "apparmor" if DEFAULT_SECURITY_APPARMOR 240 default "" if DEFAULT_SECURITY_DAC 241 242endmenu 243 244