diff options
| author | Chengming Zhou <chengming.zhou@linux.dev> | 2024-06-07 16:40:13 +0800 |
|---|---|---|
| committer | Vlastimil Babka <vbabka@suse.cz> | 2024-06-07 11:03:24 +0200 |
| commit | adef2aeaa2b936c97865d56c59be2cb7266acbb7 (patch) | |
| tree | 79957bf4bc610ff7de0112abd6b9573ccd258210 /mm/slub.c | |
| parent | 47d911b02cbe61494bb066ad84cc66d25091d506 (diff) | |
slab: don't put freepointer outside of object if only orig_size
The commit 946fa0dbf2d8 ("mm/slub: extend redzone check to extra
allocated kmalloc space than requested") will extend right redzone
when allocating for orig_size < object_size. So we can't overlay the
freepointer in the object space in this case.
But the code looks like it forgot to check SLAB_RED_ZONE, since there
won't be extended right redzone if only orig_size enabled.
As we are here, make this complex conditional expressions a little
prettier and add some comments about extending right redzone when
slub_debug_orig_size() enabled.
Reviewed-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/mm/slub.c b/mm/slub.c index 5df8c8302784..5fc052a4f38f 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5167,10 +5167,9 @@ static int calculate_sizes(struct kmem_cache *s) */ s->inuse = size; - if (slub_debug_orig_size(s) || - (flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) || - ((flags & SLAB_RED_ZONE) && s->object_size < sizeof(void *)) || - s->ctor) { + if ((flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) || s->ctor || + ((flags & SLAB_RED_ZONE) && + (s->object_size < sizeof(void *) || slub_debug_orig_size(s)))) { /* * Relocate free pointer after the object if it is not * permitted to overwrite the first word of the object on @@ -5178,7 +5177,9 @@ static int calculate_sizes(struct kmem_cache *s) * * This is the case if we do RCU, have a constructor or * destructor, are poisoning the objects, or are - * redzoning an object smaller than sizeof(void *). + * redzoning an object smaller than sizeof(void *) or are + * redzoning an object with slub_debug_orig_size() enabled, + * in which case the right redzone may be extended. * * The assumption that s->offset >= s->inuse means free * pointer is outside of the object is used in the |