kasan, kmemleak: pass tagged pointers to kmemleak

Right now we call kmemleak hooks before assigning tags to pointers in
KASAN hooks.  As a result, when an objects gets allocated, kmemleak sees a
differently tagged pointer, compared to the one it sees when the object
gets freed.  Fix it by calling KASAN hooks before kmemleak's ones.

Link: http://lkml.kernel.org/r/cd825aa4897b0fc37d3316838993881daccbe9f5.1549921721.git.andreyknvl@google.comSigned-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/slab.h

@@ -437,11 +437,9 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
 
 	flags &= gfp_allowed_mask;
 	for (i = 0; i < size; i++) {
-		void *object = p[i];
-
-		kmemleak_alloc_recursive(object, s->object_size, 1,
+		p[i] = kasan_slab_alloc(s, p[i], flags);
+		kmemleak_alloc_recursive(p[i], s->object_size, 1,
 					 s->flags, flags);
-		p[i] = kasan_slab_alloc(s, object, flags);
 	}
 
 	if (memcg_kmem_enabled())

mm/slab_common.c

@@ -1228,8 +1228,8 @@ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
 	flags |= __GFP_COMP;
 	page = alloc_pages(flags, order);
 	ret = page ? page_address(page) : NULL;
-	kmemleak_alloc(ret, size, 1, flags);
 	ret = kasan_kmalloc_large(ret, size, flags);
+	kmemleak_alloc(ret, size, 1, flags);
 	return ret;
 }
 EXPORT_SYMBOL(kmalloc_order);

mm/slub.c

@@ -1374,8 +1374,9 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node,
  */
 static inline void *kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags)
 {
+	ptr = kasan_kmalloc_large(ptr, size, flags);
 	kmemleak_alloc(ptr, size, 1, flags);
-	return kasan_kmalloc_large(ptr, size, flags);
+	return ptr;
 }
 
 static __always_inline void kfree_hook(void *x)