From:   Dominick Grift <dac.override@gmail.com>
To:     "Sugar\, David" <dsugar@tresys.com>
Cc:     "selinux-refpolicy\@vger.kernel.org" 
        <selinux-refpolicy@vger.kernel.org>
Subject: Re: [PATCH] Add interface to allow relabeling of iso 9660 filesystems.
References: <20190305223209.18922-1-dsugar@tresys.com>
Date:   Wed, 06 Mar 2019 09:20:53 +0100
In-Reply-To: <20190305223209.18922-1-dsugar@tresys.com> (David Sugar's message
        of "Tue, 5 Mar 2019 22:32:44 +0000")
Message-ID: <87wolcxvkq.fsf@gmail.com>
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"Sugar, David" <dsugar@tresys.com> writes:

> I have a case where I'm labeling media with my own types to control
> access.  But that is requiring that I relabel from iso9660_t to my
> own type.  This interface allows that relabel.

Not sure why you would want this as iso9600 is read-only any way, I
suppose you want to block read access for entities that can already read iso9660.

>
> type=AVC msg=audit(1551621984.372:919): avc:  denied  { relabelfrom } for  pid=9717 comm="mount" scontext=staff_u:staff_r:mymedia_sudo_t:s0-s0:c0.c1023 tcontext=system_u:object_r:iso9660_t:s0 tclass=filesystem permissive=0
>
> Signed-off-by: Dave Sugar <dsugar@tresys.com>
> ---
>  policy/modules/kernel/filesystem.if | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/policy/modules/kernel/filesystem.if b/policy/modules/kernel/filesystem.if
> index 048b9d65..a22cb6ba 100644
> --- a/policy/modules/kernel/filesystem.if
> +++ b/policy/modules/kernel/filesystem.if
> @@ -2505,6 +2505,25 @@ interface(`fs_remount_iso9660_fs',`
>  	allow $1 iso9660_t:filesystem remount;
>  ')
>  
> +########################################
> +## <summary>
> +##	Allow changing of the label of a
> +##	filesystem with iso9660 type
> +## </summary>
> +## <param name="domain">
> +##	<summary>
> +##	Domain allowed access.
> +##	</summary>
> +## </param>
> +#
> +interface(`fs_relabelfrom_iso9660_fs',`
> +	gen_require(`
> +		type iso9660_t;
> +	')
> +
> +	allow $1 iso9660_t:filesystem relabelfrom;
> +')
> +
>  ########################################
>  ## <summary>
>  ##	Unmount an iso9660 filesystem, which

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Dominick Grift