mm/sl[au]b: check if large object is valid in __ksize()

If address of large object is not beginning of folio or size of the
folio is too small, it must be invalid. WARN() and return 0 in such
cases.

Cc: Marco Elver <elver@google.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
This commit is contained in:
Hyeonggon Yoo 2022-08-17 19:18:26 +09:00 committed by Vlastimil Babka
parent 8dfa9d5540
commit d5eff73690
1 changed files with 6 additions and 1 deletions

View File

@ -984,8 +984,13 @@ size_t __ksize(const void *object)
folio = virt_to_folio(object);
if (unlikely(!folio_test_slab(folio)))
if (unlikely(!folio_test_slab(folio))) {
if (WARN_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE))
return 0;
if (WARN_ON(object != folio_address(folio)))
return 0;
return folio_size(folio);
}
return slab_ksize(folio_slab(folio)->slab_cache);
}