| From 757fed1d0898b893d7daa84183947c70f27632f3 Mon Sep 17 00:00:00 2001 |
| From: Wang Hai <wanghai38@huawei.com> |
| Date: Thu, 28 Jan 2021 19:32:50 +0800 |
| Subject: Revert "mm/slub: fix a memory leak in sysfs_slab_add()" |
| |
| 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(-) |
| |
| --- a/mm/slub.c |
| +++ b/mm/slub.c |
| @@ -5755,10 +5755,8 @@ static int sysfs_slab_add(struct kmem_ca |
| |
| 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) |
