From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: fix KASAN_STACK dependency for HW_TAGS 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.) Link: https://lkml.kernel.org/r/59e75426241dbb5611277758c8d4d6f5f9298dac.1615215441.git.andreyknvl@xxxxxxxxxx Fixes: 6a63a63ff1ac ("kasan: introduce CONFIG_KASAN_HW_TAGS") Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reported-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Cc: Peter Collingbourne <pcc@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/Kconfig.kasan | 1 + 1 file changed, 1 insertion(+) --- a/lib/Kconfig.kasan~kasan-fix-kasan_stack-dependency-for-hw_tags +++ a/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 _
