From 67823a544414def2a36c212abadb55b23bcda00c Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Mon, 18 Oct 2021 15:16:02 -0700 Subject: mm, slub: fix potential use-after-free in slab_debugfs_fops When sysfs_slab_add failed, we shouldn't call debugfs_slab_add() for s because s will be freed soon. And slab_debugfs_fops will use s later leading to a use-after-free. Link: https://lkml.kernel.org/r/20210916123920.48704-5-linmiaohe@huawei.com Fixes: 64dd68497be7 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs") Signed-off-by: Miaohe Lin Reviewed-by: Vlastimil Babka Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Bharata B Rao Cc: Christoph Lameter Cc: David Rientjes Cc: Faiyaz Mohammed Cc: Greg Kroah-Hartman Cc: Joonsoo Kim Cc: Kees Cook Cc: Pekka Enberg Cc: Roman Gushchin Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slub.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index bf1793fb4ce5..f3df0f04a472 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4887,13 +4887,15 @@ int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags) return 0; err = sysfs_slab_add(s); - if (err) + if (err) { __kmem_cache_release(s); + return err; + } if (s->flags & SLAB_STORE_USER) debugfs_slab_add(s); - return err; + return 0; } void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller) -- cgit v1.2.3