05883eee85
What triggers it is a race between mount --move and umount -l of the source; we should reject it (the source is parentless *and* not the root of anon namespace at that), but the check for namespace being an anon one is broken in that case - is_anon_ns() needs ns to be non-NULL. Better fixed here than in is_anon_ns(), since the rest of the callers is guaranteed to get a non-NULL argument... Reported-by: syzbot+494c7ddf66acac0ad747@syzkaller.appspotmail.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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.