diff options
| -rw-r--r-- | mm/kasan/kasan.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 98e3059bfea4..d739cdd1621a 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -9,6 +9,7 @@ #ifdef CONFIG_KASAN_HW_TAGS #include <linux/static_key.h> +#include "../slab.h" DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace); extern bool kasan_flag_async __ro_after_init; @@ -387,6 +388,17 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init) if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) return; + /* + * Explicitly initialize the memory with the precise object size to + * avoid overwriting the SLAB redzone. This disables initialization in + * the arch code and may thus lead to performance penalty. The penalty + * is accepted since SLAB redzones aren't enabled in production builds. + */ + if (__slub_debug_enabled() && + init && ((unsigned long)size & KASAN_GRANULE_MASK)) { + init = false; + memzero_explicit((void *)addr, size); + } size = round_up(size, KASAN_GRANULE_SIZE); hw_set_mem_tag_range((void *)addr, size, tag, init); |