6859985a2f
commit 1f5573cfe7a7056e80a92c7a037a3e69f3a13d1c upstream.
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 <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.