diff options
Diffstat (limited to 'mm/kasan/report_hw_tags.c')
-rw-r--r-- | mm/kasan/report_hw_tags.c | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/mm/kasan/report_hw_tags.c b/mm/kasan/report_hw_tags.c index f3d3be614e4b..32e80f78de7d 100644 --- a/mm/kasan/report_hw_tags.c +++ b/mm/kasan/report_hw_tags.c @@ -17,10 +17,43 @@ void *kasan_find_first_bad_addr(void *addr, size_t size) { - /* Return the same value regardless of whether addr_has_metadata(). */ + /* + * Hardware Tag-Based KASAN only calls this function for normal memory + * accesses, and thus addr points precisely to the first bad address + * with an invalid (and present) memory tag. Therefore: + * 1. Return the address as is without walking memory tags. + * 2. Skip the addr_has_metadata check. + */ return kasan_reset_tag(addr); } +size_t kasan_get_alloc_size(void *object, struct kmem_cache *cache) +{ + size_t size = 0; + int i = 0; + u8 memory_tag; + + /* + * Skip the addr_has_metadata check, as this function only operates on + * slab memory, which must have metadata. + */ + + /* + * The loop below returns 0 for freed objects, for which KASAN cannot + * calculate the allocation size based on the metadata. + */ + while (size < cache->object_size) { + memory_tag = hw_get_mem_tag(object + i * KASAN_GRANULE_SIZE); + if (memory_tag != KASAN_TAG_INVALID) + size += KASAN_GRANULE_SIZE; + else + return size; + i++; + } + + return cache->object_size; +} + void kasan_metadata_fetch_row(char *buffer, void *row) { int i; |