diff options
| -rw-r--r-- | mm/kasan/common.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 218b23a5a597..dcdc92948364 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -494,7 +494,6 @@ EXPORT_SYMBOL(__kasan_kmalloc); void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) { - struct page *page; unsigned long redzone_start; unsigned long redzone_end; @@ -504,12 +503,23 @@ void * __must_check __kasan_kmalloc_large(const void *ptr, size_t size, if (unlikely(ptr == NULL)) return NULL; - page = virt_to_page(ptr); + /* + * The object has already been unpoisoned by kasan_alloc_pages() for + * alloc_pages() or by ksize() for krealloc(). + */ + + /* + * The redzone has byte-level precision for the generic mode. + * Partially poison the last object granule to cover the unaligned + * part of the redzone. + */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) + kasan_poison_last_granule(ptr, size); + + /* Poison the aligned part of the redzone. */ redzone_start = round_up((unsigned long)(ptr + size), KASAN_GRANULE_SIZE); - redzone_end = (unsigned long)ptr + page_size(page); - - kasan_unpoison(ptr, size); + redzone_end = (unsigned long)ptr + page_size(virt_to_page(ptr)); kasan_poison((void *)redzone_start, redzone_end - redzone_start, KASAN_PAGE_REDZONE); |