security/Kconfig

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