On 3/6/19 3:20 AM, Dominick Grift wrote:
> "Sugar, David" <dsugar@xxxxxxxxxx> 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.
>
In what I am working on I have to support encrypted USB devices. Many
of these devices work by first presenting a read-only partition. It
shows up as /dev/sr#. This partition is used to unlock the encrypted
partition (which then shows up as /dev/sd*#).
When mounting the read-only partition I'm providing a specific context
to the mount command. I think during the mount it initially gets the
context iso9660_t and then relabels from that to my context. Note that
I am not transitioning to the call to mount, but running mount in my domain.
And I kind of do want to keep other domains from accessing this mounted
partition.
>>
>> 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@xxxxxxxxxx>
>> ---
>> 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
>
