diff mbox series

[147/192] kasan: add memory corruption identification support for hardware tag-based mode

Message ID 20210629024058.3yKEjoq_k%akpm@linux-foundation.org (mailing list archive)
State New
Headers show
Series [001/192] mm/gup: fix try_grab_compound_head() race with split_huge_page() | expand

Commit Message

Andrew Morton June 29, 2021, 2:40 a.m. UTC 
From: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Subject: 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 <Kuan-Ying.Lee@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/Kconfig.kasan |    2 +-
 mm/kasan/kasan.h  |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

--- a/lib/Kconfig.kasan~kasan-add-memory-corruption-identification-support-for-hardware-tag-based-mode
+++ a/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
--- a/mm/kasan/kasan.h~kasan-add-memory-corruption-identification-support-for-hardware-tag-based-mode
+++ a/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