summaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
Diffstat (limited to 'mm')
-rw-r--r--mm/slub.c41
1 files changed, 26 insertions, 15 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 63d281dfacdb..782bd8a6bd34 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -870,20 +870,20 @@ static inline void set_orig_size(struct kmem_cache *s,
void *object, unsigned int orig_size)
{
void *p = kasan_reset_tag(object);
+ unsigned int kasan_meta_size;
if (!slub_debug_orig_size(s))
return;
-#ifdef CONFIG_KASAN_GENERIC
/*
- * KASAN could save its free meta data in object's data area at
- * offset 0, if the size is larger than 'orig_size', it will
- * overlap the data redzone in [orig_size+1, object_size], and
- * the check should be skipped.
+ * KASAN can save its free meta data inside of the object at offset 0.
+ * If this meta data size is larger than 'orig_size', it will overlap
+ * the data redzone in [orig_size+1, object_size]. Thus, we adjust
+ * 'orig_size' to be as at least as big as KASAN's meta data.
*/
- if (kasan_metadata_size(s, true) > orig_size)
- orig_size = s->object_size;
-#endif
+ kasan_meta_size = kasan_metadata_size(s, true);
+ if (kasan_meta_size > orig_size)
+ orig_size = kasan_meta_size;
p += get_info_end(s);
p += sizeof(struct track) * 2;
@@ -1192,7 +1192,7 @@ static int check_object(struct kmem_cache *s, struct slab *slab,
{
u8 *p = object;
u8 *endobject = object + s->object_size;
- unsigned int orig_size;
+ unsigned int orig_size, kasan_meta_size;
if (s->flags & SLAB_RED_ZONE) {
if (!check_bytes_and_report(s, slab, object, "Left Redzone",
@@ -1222,12 +1222,23 @@ static int check_object(struct kmem_cache *s, struct slab *slab,
}
if (s->flags & SLAB_POISON) {
- if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) &&
- (!check_bytes_and_report(s, slab, p, "Poison", p,
- POISON_FREE, s->object_size - 1) ||
- !check_bytes_and_report(s, slab, p, "End Poison",
- p + s->object_size - 1, POISON_END, 1)))
- return 0;
+ if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON)) {
+ /*
+ * KASAN can save its free meta data inside of the
+ * object at offset 0. Thus, skip checking the part of
+ * the redzone that overlaps with the meta data.
+ */
+ kasan_meta_size = kasan_metadata_size(s, true);
+ if (kasan_meta_size < s->object_size - 1 &&
+ !check_bytes_and_report(s, slab, p, "Poison",
+ p + kasan_meta_size, POISON_FREE,
+ s->object_size - kasan_meta_size - 1))
+ return 0;
+ if (kasan_meta_size < s->object_size &&
+ !check_bytes_and_report(s, slab, p, "End Poison",
+ p + s->object_size - 1, POISON_END, 1))
+ return 0;
+ }
/*
* check_pad_bytes cleans up on its own.
*/