From: Matthew Wilcox <willy@infradead.org>
To: Sagi Grimberg <sagi@grimberg.me>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jens Axboe <axboe@fb.com>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
Stephen Bates <sbates@raithlin.com>,
linux-block@vger.kernel.org, Keith Busch <kbusch@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org, Max Gurtovoy <maxg@mellanox.com>,
Logan Gunthorpe <logang@deltatee.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v6 02/16] chardev: introduce cdev_get_by_path()
Date: Thu, 25 Jul 2019 12:11:25 -0700 [thread overview]
Message-ID: <20190725191124.GE30641@bombadil.infradead.org> (raw)
In-Reply-To: <27943e06-a503-162e-356b-abb9e106ab2e@grimberg.me>
On Thu, Jul 25, 2019 at 12:05:29PM -0700, Sagi Grimberg wrote:
>
> > > > NVMe-OF is configured using configfs. The target is specified by the
> > > > user writing a path to a configfs attribute. This is the way it works
> > > > today but with blkdev_get_by_path()[1]. For the passthru code, we need
> > > > to get a nvme_ctrl instead of a block_device, but the principal is the same.
> > >
> > > Why isn't a fd being passed in there instead of a random string?
> >
> > I suppose we could echo a string of the file descriptor number there,
> > and look up the fd in the process' file descriptor table ...
>
> Assuming that there is a open handle somewhere out there...
Well, that's how we'd know that the application echoing /dev/nvme3 into
configfs actually has permission to access /dev/nvme3. Think about
containers, for example. It's not exactly safe to mount configfs in a
non-root container since it can access any NVMe device in the system,
not just ones which it's been given permission to access. Right?
WARNING: multiple messages have this Message-ID (diff)
From: willy@infradead.org (Matthew Wilcox)
Subject: [PATCH v6 02/16] chardev: introduce cdev_get_by_path()
Date: Thu, 25 Jul 2019 12:11:25 -0700 [thread overview]
Message-ID: <20190725191124.GE30641@bombadil.infradead.org> (raw)
In-Reply-To: <27943e06-a503-162e-356b-abb9e106ab2e@grimberg.me>
On Thu, Jul 25, 2019@12:05:29PM -0700, Sagi Grimberg wrote:
>
> > > > NVMe-OF is configured using configfs. The target is specified by the
> > > > user writing a path to a configfs attribute. This is the way it works
> > > > today but with blkdev_get_by_path()[1]. For the passthru code, we need
> > > > to get a nvme_ctrl instead of a block_device, but the principal is the same.
> > >
> > > Why isn't a fd being passed in there instead of a random string?
> >
> > I suppose we could echo a string of the file descriptor number there,
> > and look up the fd in the process' file descriptor table ...
>
> Assuming that there is a open handle somewhere out there...
Well, that's how we'd know that the application echoing /dev/nvme3 into
configfs actually has permission to access /dev/nvme3. Think about
containers, for example. It's not exactly safe to mount configfs in a
non-root container since it can access any NVMe device in the system,
not just ones which it's been given permission to access. Right?
next prev parent reply other threads:[~2019-07-25 19:11 UTC|newest]
Thread overview: 122+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-25 17:23 [PATCH v6 00/16] nvmet: add target passthru commands support Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 01/16] chardev: factor out cdev_lookup() helper Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 02/16] chardev: introduce cdev_get_by_path() Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:40 ` Greg Kroah-Hartman
2019-07-25 17:40 ` Greg Kroah-Hartman
2019-07-25 17:53 ` Logan Gunthorpe
2019-07-25 17:53 ` Logan Gunthorpe
2019-07-25 17:58 ` Matthew Wilcox
2019-07-25 17:58 ` Matthew Wilcox
2019-07-25 18:08 ` Logan Gunthorpe
2019-07-25 18:08 ` Logan Gunthorpe
2019-07-25 18:08 ` Greg Kroah-Hartman
2019-07-25 18:08 ` Greg Kroah-Hartman
2019-07-25 18:14 ` Logan Gunthorpe
2019-07-25 18:14 ` Logan Gunthorpe
2019-07-25 18:27 ` Greg Kroah-Hartman
2019-07-25 18:27 ` Greg Kroah-Hartman
2019-07-25 18:36 ` Logan Gunthorpe
2019-07-25 18:36 ` Logan Gunthorpe
2019-07-25 19:02 ` Sagi Grimberg
2019-07-25 19:02 ` Sagi Grimberg
2019-07-25 19:34 ` Greg Kroah-Hartman
2019-07-25 19:34 ` Greg Kroah-Hartman
2019-07-25 19:37 ` Sagi Grimberg
2019-07-25 19:37 ` Sagi Grimberg
2019-07-25 19:43 ` Greg Kroah-Hartman
2019-07-25 19:43 ` Greg Kroah-Hartman
2019-07-25 19:45 ` Sagi Grimberg
2019-07-25 19:45 ` Sagi Grimberg
2019-07-25 19:43 ` Sagi Grimberg
2019-07-25 19:43 ` Sagi Grimberg
2019-07-25 19:41 ` Logan Gunthorpe
2019-07-25 19:41 ` Logan Gunthorpe
2019-07-25 19:00 ` Matthew Wilcox
2019-07-25 19:00 ` Matthew Wilcox
2019-07-25 19:05 ` Sagi Grimberg
2019-07-25 19:05 ` Sagi Grimberg
2019-07-25 19:11 ` Matthew Wilcox [this message]
2019-07-25 19:11 ` Matthew Wilcox
2019-07-25 19:24 ` Logan Gunthorpe
2019-07-25 19:24 ` Logan Gunthorpe
2019-07-25 19:26 ` Matthew Wilcox
2019-07-25 19:26 ` Matthew Wilcox
2019-07-25 19:31 ` Logan Gunthorpe
2019-07-25 19:31 ` Logan Gunthorpe
2019-07-25 23:55 ` Al Viro
2019-07-25 23:55 ` Al Viro
2019-07-26 4:29 ` Sagi Grimberg
2019-07-26 4:29 ` Sagi Grimberg
2019-07-26 7:13 ` Greg Kroah-Hartman
2019-07-26 7:13 ` Greg Kroah-Hartman
2019-07-26 15:46 ` Logan Gunthorpe
2019-07-26 15:46 ` Logan Gunthorpe
2019-07-25 19:31 ` Sagi Grimberg
2019-07-25 19:31 ` Sagi Grimberg
2019-07-25 18:10 ` Greg Kroah-Hartman
2019-07-25 18:10 ` Greg Kroah-Hartman
2019-07-25 18:16 ` Logan Gunthorpe
2019-07-25 18:16 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 03/16] chardev: export cdev_put() Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 04/16] nvme-core: introduce nvme_get_by_path() Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:50 ` Matthew Wilcox
2019-07-25 17:50 ` Matthew Wilcox
2019-07-25 17:54 ` Logan Gunthorpe
2019-07-25 17:54 ` Logan Gunthorpe
2019-07-25 19:58 ` Keith Busch
2019-07-25 19:58 ` Keith Busch
2019-07-25 20:12 ` Sagi Grimberg
2019-07-25 20:12 ` Sagi Grimberg
2019-07-25 20:28 ` Logan Gunthorpe
2019-07-25 20:28 ` Logan Gunthorpe
2019-07-25 20:31 ` Keith Busch
2019-07-25 20:31 ` Keith Busch
2019-07-25 20:37 ` Logan Gunthorpe
2019-07-25 20:37 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 05/16] nvme-core: export existing ctrl and ns interfaces Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 06/16] nvmet: add return value to nvmet_add_async_event() Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 07/16] nvmet: make nvmet_copy_ns_identifier() non-static Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 08/16] nvmet-passthru: update KConfig with config passthru option Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 09/16] nvmet-passthru: add passthru code to process commands Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 10/16] nvmet-passthru: add enable/disable helpers Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 11/16] nvmet-core: allow one host per passthru-ctrl Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 12/16] nvmet-core: don't check the data len for pt-ctrl Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 13/16] nvmet-configfs: introduce passthru configfs interface Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 14/16] block: don't check blk_rq_is_passthrough() in blk_do_io_stat() Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 15/16] block: call blk_account_io_start() in blk_execute_rq_nowait() Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 16/16] nvmet-passthru: support block accounting Logan Gunthorpe
2019-07-25 17:23 ` Logan Gunthorpe
2019-07-26 6:23 ` [PATCH v6 00/16] nvmet: add target passthru commands support Hannes Reinecke
2019-07-26 6:23 ` Hannes Reinecke
2019-07-26 17:07 ` Logan Gunthorpe
2019-07-26 17:07 ` Logan Gunthorpe
2019-07-26 22:21 ` Sagi Grimberg
2019-07-26 22:21 ` Sagi Grimberg
2019-07-26 22:37 ` Logan Gunthorpe
2019-07-26 22:37 ` Logan Gunthorpe
2019-07-26 23:13 ` Sagi Grimberg
2019-07-26 23:13 ` Sagi Grimberg
2019-07-27 0:09 ` Logan Gunthorpe
2019-07-27 0:09 ` Logan Gunthorpe
2019-07-27 0:50 ` Stephen Bates
2019-07-27 0:50 ` Stephen Bates
2019-07-29 16:15 ` Sagi Grimberg
2019-07-29 16:15 ` Sagi Grimberg
2019-07-29 16:17 ` Logan Gunthorpe
2019-07-29 16:17 ` Logan Gunthorpe
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