From: Wang Hai <wanghai38@huawei.com> commit 757fed1d0898b893d7daa84183947c70f27632f3 upstream. This reverts commit dde3c6b72a16c2db826f54b2d49bdea26c3534a2. syzbot report a double-free bug. The following case can cause this bug. - mm/slab_common.c: create_cache(): if the __kmem_cache_create() fails, it does: out_free_cache: kmem_cache_free(kmem_cache, s); - but __kmem_cache_create() - at least for slub() - will have done sysfs_slab_add(s) -> sysfs_create_group() .. fails .. -> kobject_del(&s->kobj); .. which frees s ... We can't remove the kmem_cache_free() in create_cache(), because other error cases of __kmem_cache_create() do not free this. So, revert the commit dde3c6b72a16 ("mm/slub: fix a memory leak in sysfs_slab_add()") to fix this. Reported-by: syzbot+d0bd96b4696c1ef67991@syzkaller.appspotmail.com Fixes: dde3c6b72a16 ("mm/slub: fix a memory leak in sysfs_slab_add()") Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Wang Hai <wanghai38@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- mm/slub.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 182b403b7ec6..f5e94499b736 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5746,10 +5746,8 @@ static int sysfs_slab_add(struct kmem_cache *s) s->kobj.kset = kset; err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name); - if (err) { - kobject_put(&s->kobj); + if (err) goto out; - } err = sysfs_create_group(&s->kobj, &slab_attr_group); if (err) -- 2.25.1