Messages in this thread Patch in this message | | | From | Alexander Popov <> | Subject | [PATCH 1/1] mm/slub.c: add a naive detection of double free or corruption | Date | Mon, 17 Jul 2017 19:45:07 +0300 |
| |
Add an assertion similar to "fasttop" check in GNU C Library allocator: an object added to a singly linked freelist should not point to itself. That helps to detect some double free errors (e.g. CVE-2017-2636) without slub_debug and KASAN. Testing with hackbench doesn't show any noticeable performance penalty.
Signed-off-by: Alexander Popov <alex.popov@linux.com> --- mm/slub.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/mm/slub.c b/mm/slub.c index 1d3f983..a106939b 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -261,6 +261,7 @@ static inline void *get_freepointer_safe(struct kmem_cache *s, void *object) static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) { + BUG_ON(object == fp); /* naive detection of double free or corruption */ *(void **)(object + s->offset) = fp; } -- 2.7.4
| |