From 1f5573cfe7a7056e80a92c7a037a3e69f3a13d1c Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 4 Nov 2021 10:55:34 +0100 Subject: ovl: fix warning in ovl_create_real() Syzbot triggered the following warning in ovl_workdir_create() -> ovl_create_real(): if (!err && WARN_ON(!newdentry->d_inode)) { The reason is that the cgroup2 filesystem returns from mkdir without instantiating the new dentry. Weird filesystems such as this will be rejected by overlayfs at a later stage during setup, but to prevent such a warning, call ovl_mkdir_real() directly from ovl_workdir_create() and reject this case early. Reported-and-tested-by: syzbot+75eab84fd0af9e8bf66b@syzkaller.appspotmail.com Signed-off-by: Miklos Szeredi --- fs/overlayfs/overlayfs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/overlayfs/overlayfs.h') diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 3894f3347955..2cd5741c873b 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -570,6 +570,7 @@ struct ovl_cattr { #define OVL_CATTR(m) (&(struct ovl_cattr) { .mode = (m) }) +int ovl_mkdir_real(struct inode *dir, struct dentry **newdentry, umode_t mode); struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry, struct ovl_cattr *attr); int ovl_cleanup(struct inode *dir, struct dentry *dentry); -- cgit v1.2.3