Re: [PATCH AUTOSEL 4.20 43/81] blk-mq: protect debugfs_create_files() from failures

Greg Kroah-Hartman
2019-02-28T15:26:21Z

On Thu, Feb 28, 2019 at 10:07:35AM -0500, Sasha Levin wrote:
> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>
> [ Upstream commit 36991ca68db9dd43bac7f3519f080ee3939263ef ]
>
> If debugfs were to return a non-NULL error for a debugfs call, using
> that pointer later in debugfs_create_files() would crash.
>
> Fix that by properly checking the pointer before referencing it.
>
> Reported-by: Michal Hocko <mhocko@kernel.org>
> Reported-and-tested-by: syzbot+b382ba6a802a3d242790@syzkaller.appspotmail.com
> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> block/blk-mq-debugfs.c | 3 +++
> 1 file changed, 3 insertions(+)
>

As the commit this "fixes" should not be backported, no need for this
patch in any stable kernel either. Please drop from all queues.

thanks,

greg k-h