From 7a22bdc3c443d5abc420df1381e425b49e8901a3 Mon Sep 17 00:00:00 2001 From: Kuan-Ying Lee Date: Mon, 28 Jun 2021 19:40:58 -0700 Subject: [PATCH] kasan: add memory corruption identification support for hardware tag-based mode Add memory corruption identification support for hardware tag-based mode. We store one old free pointer tag and free backtrace instead of five because hardware tag-based kasan only has 16 different tags. If we store as many stacks as SW tag-based kasan does(5 stacks), there is high probability to find the same tag in the stacks when out-of-bound issues happened and we will mistake out-of-bound issue for use-after-free. Link: https://lkml.kernel.org/r/20210626100931.22794-4-Kuan-Ying.Lee@mediatek.com Signed-off-by: Kuan-Ying Lee Suggested-by: Marco Elver Reviewed-by: Alexander Potapenko Reviewed-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Chinwen Chang Cc: Greg Kroah-Hartman Cc: Matthias Brugger Cc: Nicholas Tang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.kasan | 2 +- mm/kasan/kasan.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index fdb4a08dba83..1e2d10f86011 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -169,7 +169,7 @@ config KASAN_STACK config KASAN_TAGS_IDENTIFY bool "Enable memory corruption identification" - depends on KASAN_SW_TAGS + depends on KASAN_SW_TAGS || KASAN_HW_TAGS help This option enables best-effort identification of bug type (use-after-free or out-of-bounds) at the cost of increased diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 2317d0943a07..98e3059bfea4 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -153,7 +153,7 @@ struct kasan_track { depot_stack_handle_t stack; }; -#ifdef CONFIG_KASAN_TAGS_IDENTIFY +#if defined(CONFIG_KASAN_TAGS_IDENTIFY) && defined(CONFIG_KASAN_SW_TAGS) #define KASAN_NR_FREE_STACKS 5 #else #define KASAN_NR_FREE_STACKS 1 -- 2.11.0