Wire up CONFIG_STACKLEAK to Clang 21's new stack depth tracking callback[1] option.
Link: https://clang.llvm.org/docs/SanitizerCoverage.html#tracing-stack-depth [1] Signed-off-by: Kees Cook kees@kernel.org --- Cc: Arnd Bergmann arnd@arndb.de Cc: Masahiro Yamada masahiroy@kernel.org Cc: Nathan Chancellor nathan@kernel.org Cc: Nicolas Schier nicolas.schier@linux.dev Cc: Marco Elver elver@google.com Cc: Andrey Konovalov andreyknvl@gmail.com Cc: Andrey Ryabinin ryabinin.a.a@gmail.com Cc: Ard Biesheuvel ardb@kernel.org Cc: "Gustavo A. R. Silva" gustavoars@kernel.org Cc: linux-kbuild@vger.kernel.org Cc: kasan-dev@googlegroups.com Cc: linux-hardening@vger.kernel.org --- security/Kconfig.hardening | 5 ++++- scripts/Makefile.stackleak | 6 ++++++ 2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index 2be6aed71c92..94aa8612c4e4 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -158,10 +158,13 @@ config GCC_PLUGIN_STRUCTLEAK_VERBOSE initialized. Since not all existing initializers are detected by the plugin, this can produce false positive warnings.
+config CC_HAS_SANCOV_STACK_DEPTH_CALLBACK + def_bool $(cc-option,-fsanitize-coverage-stack-depth-callback-min=1) + config STACKLEAK bool "Poison kernel stack before returning from syscalls" depends on HAVE_ARCH_STACKLEAK - depends on GCC_PLUGINS + depends on GCC_PLUGINS || CC_HAS_SANCOV_STACK_DEPTH_CALLBACK help This option makes the kernel erase the kernel stack before returning from system calls. This has the effect of leaving diff --git a/scripts/Makefile.stackleak b/scripts/Makefile.stackleak index 1db0835b29d4..639cc32bcd1d 100644 --- a/scripts/Makefile.stackleak +++ b/scripts/Makefile.stackleak @@ -8,6 +8,12 @@ stackleak-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK_VERBOSE) += -fplugin-arg-stacklea DISABLE_STACKLEAK := -fplugin-arg-stackleak_plugin-disable endif
+ifdef CONFIG_CC_IS_CLANG +stackleak-cflags-y += -fsanitize-coverage=stack-depth +stackleak-cflags-y += -fsanitize-coverage-stack-depth-callback-min=$(CONFIG_STACKLEAK_TRACK_MIN_SIZE) +DISABLE_STACKLEAK := -fno-sanitize-coverage=stack-depth +endif + STACKLEAK_CFLAGS := $(stackleak-cflags-y)
export STACKLEAK_CFLAGS DISABLE_STACKLEAK