From mboxrd@z Thu Jan  1 00:00:00 1970
From: Richard Weinberger <richard.weinberger-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH 02/11] mtd: Check permissions towards mtd block device
	inode when mounting
Date: Fri, 22 Dec 2017 22:06:13 +0100
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To: Dongsu Park <dongsu-lYLaGTFnO9sWenYVfaLwtA@public.gmane.org>
Cc: Miklos Szeredi <mszeredi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Linux Containers <containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>, LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Seth Forshee <seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>, Alban Crequy <alban-lYLaGTFnO9sWenYVfaLwtA@public.gmane.org>, "Eric W . Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>, Sargun Dhillon <sargun-GaZTRHToo+CzQB+pC5nmwQ@public.gmane.org>, "linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" <linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>
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Dongsu,

On Fri, Dec 22, 2017 at 3:32 PM, Dongsu Park <dongsu-lYLaGTFnO9sWenYVfaLwtA@public.gmane.org> wrote:
> From: Seth Forshee <seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
>
> Unprivileged users should not be able to mount mtd block devices
> when they lack sufficient privileges towards the block device
> inode.  Update mount_mtd() to validate that the user has the
> required access to the inode at the specified path. The check
> will be skipped for CAP_SYS_ADMIN, so privileged mounts will
> continue working as before.

What is the big picture of this?
Can in future an unprivileged user just mount UBIFS?
Please note that UBIFS sits on top of a character device and not a block device.

-- 
Thanks,
//richard