11d7a2e429
commit 9845664b9e upstream.
There's a syzbot report that device name buffers passed to device
replace are not properly checked for string termination which could lead
to a read out of bounds in getname_kernel().
Add a helper that validates both source and target device name buffers.
For devid as the source initialize the buffer to empty string in case
something tries to read it later.
This was originally analyzed and fixed in a different way by Edward Adam
Davis (see links).
Link: https://lore.kernel.org/linux-btrfs/000000000000d1a1d1060cc9c5e7@google.com/
Link: https://lore.kernel.org/linux-btrfs/tencent_44CA0665C9836EF9EEC80CB9E7E206DF5206@qq.com/
CC: stable@vger.kernel.org # 4.19+
CC: Edward Adam Davis <eadavis@qq.com>
Reported-and-tested-by: syzbot+33f23b49ac24f986c9e8@syzkaller.appspotmail.com
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.