From d9b571c885a8974fbb7d4ee639dbc643fd000f9e Mon Sep 17 00:00:00 2001
From: Andrey Konovalov <andreyknvl@google.com>
Date: Fri, 12 Mar 2021 21:08:13 -0800
Subject: [PATCH] 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@google.com
Fixes: 6a63a63ff1ac ("kasan: introduce CONFIG_KASAN_HW_TAGS")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
lib/Kconfig.kasan | 1 +
1 file changed, 1 insertion(+)
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index 624ae1df7984c..fba9909e31b71 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
--
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