diff --git a/Makefile b/Makefile index c0a34064c5744e44ca696b3dd5bdb2ea809384e0..a7d9c6cd02671b6efd3e4752e0a263763e5a7f47 100644 --- a/Makefile +++ b/Makefile @@ -745,6 +745,11 @@ KBUILD_CFLAGS += -fomit-frame-pointer endif endif +# Initialize all stack variables with a pattern, if desired. +ifdef CONFIG_INIT_STACK_ALL +KBUILD_CFLAGS += -ftrivial-auto-var-init=pattern +endif + DEBUG_CFLAGS := $(call cc-option, -fno-var-tracking-assignments) ifdef CONFIG_DEBUG_INFO diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index a96d4a43ca653a9e050aa92092c0c1720e24072c..0a1d4ca314f4711743d0a995cae91f2e8973c4ec 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -18,9 +18,13 @@ config GCC_PLUGIN_STRUCTLEAK menu "Memory initialization" +config CC_HAS_AUTO_VAR_INIT + def_bool $(cc-option,-ftrivial-auto-var-init=pattern) + choice prompt "Initialize kernel stack variables at function entry" default GCC_PLUGIN_STRUCTLEAK_BYREF_ALL if COMPILE_TEST && GCC_PLUGINS + default INIT_STACK_ALL if COMPILE_TEST && CC_HAS_AUTO_VAR_INIT default INIT_STACK_NONE help This option enables initialization of stack variables at @@ -76,6 +80,16 @@ choice of uninitialized stack variable exploits and information exposures. + config INIT_STACK_ALL + bool "0xAA-init everything on the stack (strongest)" + depends on CC_HAS_AUTO_VAR_INIT + help + Initializes everything on the stack with a 0xAA + pattern. This is intended to eliminate all classes + of uninitialized stack variable exploits and information + exposures, even variables that were warned to have been + left uninitialized. + endchoice config GCC_PLUGIN_STRUCTLEAK_VERBOSE