mainline inclusion
from mainline-v5.1-rc1
commit 720db068
category: bugfix
bugzilla: 13690
CVE: CVE-2019-9445

-------------------------------------------------

Dentry bitmap is not enough to detect incorrect dentries. So this patch
also checks the namelen value of a dentry.
Signed-off-by: NGong Chen <gongchen4@huawei.com>
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NWei Fang <fangwei1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>