8e89bf80ce
commite0c6791d04("BACKPORT: security: Create "kernel hardening" config area") introduced an x86 build breakage in allmodconfig mode. Copying the definition of GCC_PLUGIN_STRUCTLEAK_BYREF_ALL from upstream version of security/Kconfig.hardening fixes the build. Change-Id: I2def59283b829b8af8fa343eb1d4ebaa3f2e145d Reported-by: Todd Kjos <tkjos@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Bug: 143965122 Fixes:e0c6791d04("BACKPORT: security: Create "kernel hardening" config area) Test: manual - run `make allmodconfig && make -j64` Signed-off-by: Todd Kjos <tkjos@google.com>
110 lines
4.2 KiB
Plaintext
110 lines
4.2 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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menu "Kernel hardening options"
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config GCC_PLUGIN_STRUCTLEAK
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bool "Force initialization of variables containing userspace addresses"
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help
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This plugin zero-initializes any structures containing a
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__user attribute. This can prevent some classes of information
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exposures.
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This plugin was ported from grsecurity/PaX. More information at:
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* https://grsecurity.net/
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* https://pax.grsecurity.net/
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menu "Memory initialization"
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config CC_HAS_AUTO_VAR_INIT
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def_bool $(cc-option,-ftrivial-auto-var-init=pattern)
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choice
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prompt "Initialize kernel stack variables at function entry"
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default GCC_PLUGIN_STRUCTLEAK_BYREF_ALL if COMPILE_TEST && GCC_PLUGINS
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default INIT_STACK_ALL if COMPILE_TEST && CC_HAS_AUTO_VAR_INIT
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default INIT_STACK_NONE
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help
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This option enables initialization of stack variables at
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function entry time. This has the possibility to have the
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greatest coverage (since all functions can have their
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variables initialized), but the performance impact depends
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on the function calling complexity of a given workload's
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syscalls.
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This chooses the level of coverage over classes of potentially
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uninitialized variables. The selected class will be
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initialized before use in a function.
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config INIT_STACK_NONE
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bool "no automatic initialization (weakest)"
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help
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Disable automatic stack variable initialization.
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This leaves the kernel vulnerable to the standard
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classes of uninitialized stack variable exploits
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and information exposures.
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config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
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bool "zero-init anything passed by reference (very strong)"
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depends on GCC_PLUGINS
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select GCC_PLUGIN_STRUCTLEAK
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help
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Zero-initialize any stack variables that may be passed
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by reference and had not already been explicitly
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initialized. This is intended to eliminate all classes
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of uninitialized stack variable exploits and information
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exposures.
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config INIT_STACK_ALL
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bool "0xAA-init everything on the stack (strongest)"
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depends on CC_HAS_AUTO_VAR_INIT
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help
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Initializes everything on the stack with a 0xAA
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pattern. This is intended to eliminate all classes
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of uninitialized stack variable exploits and information
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exposures, even variables that were warned to have been
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left uninitialized.
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endchoice
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config GCC_PLUGIN_STRUCTLEAK_VERBOSE
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bool "Report forcefully initialized variables"
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depends on GCC_PLUGIN_STRUCTLEAK
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depends on !COMPILE_TEST # too noisy
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help
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This option will cause a warning to be printed each time the
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structleak plugin finds a variable it thinks needs to be
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initialized. Since not all existing initializers are detected
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by the plugin, this can produce false positive warnings.
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config INIT_ON_ALLOC_DEFAULT_ON
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bool "Enable heap memory zeroing on allocation by default"
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help
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This has the effect of setting "init_on_alloc=1" on the kernel
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command line. This can be disabled with "init_on_alloc=0".
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When "init_on_alloc" is enabled, all page allocator and slab
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allocator memory will be zeroed when allocated, eliminating
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many kinds of "uninitialized heap memory" flaws, especially
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heap content exposures. The performance impact varies by
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workload, but most cases see <1% impact. Some synthetic
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workloads have measured as high as 7%.
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config INIT_ON_FREE_DEFAULT_ON
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bool "Enable heap memory zeroing on free by default"
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help
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This has the effect of setting "init_on_free=1" on the kernel
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command line. This can be disabled with "init_on_free=0".
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Similar to "init_on_alloc", when "init_on_free" is enabled,
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all page allocator and slab allocator memory will be zeroed
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when freed, eliminating many kinds of "uninitialized heap memory"
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flaws, especially heap content exposures. The primary difference
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with "init_on_free" is that data lifetime in memory is reduced,
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as anything freed is wiped immediately, making live forensics or
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cold boot memory attacks unable to recover freed memory contents.
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The performance impact varies by workload, but is more expensive
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than "init_on_alloc" due to the negative cache effects of
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touching "cold" memory areas. Most cases see 3-5% impact. Some
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synthetic workloads have measured as high as 8%.
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endmenu
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endmenu
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