Re: [PATCH v4 3/3] kasan: Make addr_has_metadata() return true for valid addresses

Currently, addr_has_metadata() returns true for every address.
An invalid address (e.g. NULL) passed to the function when,
KASAN_HW_TAGS is enabled, leads to a kernel panic.

Make addr_has_metadata() return true for valid addresses only.

Note: KASAN_HW_TAGS support for vmalloc will be added with a future
patch.

Cc: Andrey Ryabinin <redacted>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Leon Romanovsky <redacted>
Cc: Andrey Konovalov <redacted>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 mm/kasan/kasan.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index cc4d9e1d49b1..8c706e7652f2 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h

@@ -209,7 +209,7 @@ bool check_memory_region(unsigned long addr, size_t size, bool write,

 static inline bool addr_has_metadata(const void *addr)
 {
-       return true;
+       return (is_vmalloc_addr(addr) || virt_addr_valid(addr));
 }

 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
--

2.30.0