From: Yee Lee <yee.lee@xxxxxxxxxxxx>
Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite the redzone with unaligned object size.
An additional memzero_explicit() path is added to replacing hwtag initialization
at SLUB deubg mode.
Signed-off-by: Yee Lee <yee.lee@xxxxxxxxxxxx>
Suggested-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/kasan.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index d8faa64614b7..e984a9ac814d 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -387,10 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
return;
+ #if IS_ENABLED(CONFIG_SLUB_DEBUG)
if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
init = false;
- memset((void *)addr, 0, size);
+ memzero_explicit((void *)addr, size);
}
+ #endif
size = round_up(size, KASAN_GRANULE_SIZE);
hw_set_mem_tag_range((void *)addr, size, tag, init);
}
--
2.18.0
