There's a runtime failure when running HW_TAGS-enabled kernel built with GCC on hardware that doesn't support MTE. GCC-built kernels always have CONFIG_KASAN_STACK enabled, even though stack instrumentation isn't supported by HW_TAGS. Having that config enabled causes KASAN to issue MTE-only instructions to unpoison kernel stacks, which causes the failure.
Fix the issue by disallowing CONFIG_KASAN_STACK when HW_TAGS is used.
(The commit that introduced CONFIG_KASAN_HW_TAGS specified proper dependency for CONFIG_KASAN_STACK_ENABLE but not for CONFIG_KASAN_STACK.)
Fixes: 6a63a63ff1ac ("kasan: introduce CONFIG_KASAN_HW_TAGS") Cc: stable@vger.kernel.org Reported-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Andrey Konovalov andreyknvl@google.com --- lib/Kconfig.kasan | 1 + 1 file changed, 1 insertion(+)
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index 624ae1df7984..fba9909e31b7 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -156,6 +156,7 @@ config KASAN_STACK_ENABLE
config KASAN_STACK int + depends on KASAN_GENERIC || KASAN_SW_TAGS default 1 if KASAN_STACK_ENABLE || CC_IS_GCC default 0