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 161source security/selinux/Kconfig 162source security/smack/Kconfig 163source security/tomoyo/Kconfig 164source security/apparmor/Kconfig 165source security/loadpin/Kconfig 166source security/yama/Kconfig 167 168source security/integrity/Kconfig 169 170choice 171 prompt "Default security module" 172 default DEFAULT_SECURITY_SELINUX if SECURITY_SELINUX 173 default DEFAULT_SECURITY_SMACK if SECURITY_SMACK 174 default DEFAULT_SECURITY_TOMOYO if SECURITY_TOMOYO 175 default DEFAULT_SECURITY_APPARMOR if SECURITY_APPARMOR 176 default DEFAULT_SECURITY_DAC 177 178 help 179 Select the security module that will be used by default if the 180 kernel parameter security= is not specified. 181 182 config DEFAULT_SECURITY_SELINUX 183 bool "SELinux" if SECURITY_SELINUX=y 184 185 config DEFAULT_SECURITY_SMACK 186 bool "Simplified Mandatory Access Control" if SECURITY_SMACK=y 187 188 config DEFAULT_SECURITY_TOMOYO 189 bool "TOMOYO" if SECURITY_TOMOYO=y 190 191 config DEFAULT_SECURITY_APPARMOR 192 bool "AppArmor" if SECURITY_APPARMOR=y 193 194 config DEFAULT_SECURITY_DAC 195 bool "Unix Discretionary Access Controls" 196 197endchoice 198 199config DEFAULT_SECURITY 200 string 201 default "selinux" if DEFAULT_SECURITY_SELINUX 202 default "smack" if DEFAULT_SECURITY_SMACK 203 default "tomoyo" if DEFAULT_SECURITY_TOMOYO 204 default "apparmor" if DEFAULT_SECURITY_APPARMOR 205 default "" if DEFAULT_SECURITY_DAC 206 207endmenu 208 209