[PATCH 1/3] lsm,io_uring: add LSM hooks for the new uring_cmd file op

[Paul Moore]

On Wed, Aug 24, 2022 at 2:12 AM Greg Kroah-Hartman
<gregkh at linuxfoundation.org> wrote:
> On Tue, Aug 23, 2022 at 12:48:30PM -0400, Paul Moore wrote:
> > On Tue, Aug 23, 2022 at 2:53 AM Greg Kroah-Hartman
> > <gregkh at linuxfoundation.org> wrote:
> > > On Mon, Aug 22, 2022 at 05:21:07PM -0400, Paul Moore wrote:
> > > > From: Luis Chamberlain <mcgrof at kernel.org>
> > > >
> > > > io-uring cmd support was added through ee692a21e9bf ("fs,io_uring:
> > > > add infrastructure for uring-cmd"), this extended the struct
> > > > file_operations to allow a new command which each subsystem can use
> > > > to enable command passthrough. Add an LSM specific for the command
> > > > passthrough which enables LSMs to inspect the command details.
> > > >
> > > > This was discussed long ago without no clear pointer for something
> > > > conclusive, so this enables LSMs to at least reject this new file
> > > > operation.
> > > >
> > > > [0] https://lkml.kernel.org/r/8adf55db-7bab-f59d-d612-ed906b948d19@schaufler-ca.com
> > > >
> > > > Fixes: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd")
> > >
> > > You are not "fixing" anything, you are adding new functionality.
> > > Careful with using "Fixes:" for something like this, you will trigger
> > > the bug-detection scripts and have to fend off stable bot emails for a
> > > long time for stuff that should not be backported to stable trees.
> >
> > This patch, as well as the SELinux and (soon to come) Smack hook
> > implementations, fix a LSM access control regression that occured when
> > the IORING_OP_URING_CMD functionality was merged in v5.19.  You may
> > disagree about this being a regression Greg, but there are at least
> > three people with their name on this patch that believe it is
> > important: Luis (patch author), Jens (io_uring maintainer), and myself
> > (LSM, SELinux maintainer).
>
> Ok, I'll let it be, but note that "Fixes:" tags do not mean that a patch
> will ever get backported to a stable tree, so I guess we don't have to
> worry about it :)

Ha!  Now that's the *proper* LSM dismissing GregKH comment this thread
was missing :)

-- 
paul-moore.com