Re: /etc/initscript breaks SELinux

["Justin P. Mattock" <justinmattock@gmail.com>]

On 05/03/2010 10:32 AM, Stephen Smalley wrote:
> On Mon, 2010-05-03 at 10:29 -0700, Justin P. Mattock wrote:
>> On 05/03/2010 10:02 AM, Stephen Smalley wrote:
>>> On Mon, 2010-05-03 at 09:56 -0700, Justin P. Mattock wrote:
>>>> On 05/03/2010 09:31 AM, Stephen Smalley wrote:
>>>>> On Sun, 2010-05-02 at 21:54 -0700, Justin Mattock wrote:
>>>>>> I've been racking my brain for the last few days on
>>>>>> this one, and seem(for the life of me), have no solution.
>>>>>>
>>>>>> at first thought this was opensuse specific, but it's not
>>>>>> i.g. my cblfs systems hit this as well(if not all systems at that).
>>>>>>
>>>>>> when adding /etc/initscript somehow SELinux can't figure how to
>>>>>> transistion with the whole SHELL -c thing.
>>>>>>
>>>>>> under init.c #800(sysvinit-2.85)
>>>>>> the code is this:
>>>>>>
>>>>>>     /* See if there is an "initscript" (except in single user mode). */
>>>>>>      if (access(INITSCRIPT, R_OK) == 0&&    runlevel != 'S') {
>>>>>> 	/* Build command line using "initscript" */
>>>>>> 	args[1] = SHELL;
>>>>>> 	args[2] = INITSCRIPT;
>>>>>> 	args[3] = ch->id;
>>>>>> 	args[4] = ch->rlevel;
>>>>>> 	args[5] = "unknown";
>>>>>> 	for(f = 0; actions[f].name; f++) {
>>>>>> 		if (ch->action == actions[f].act) {
>>>>>> 			args[5] = actions[f].name;
>>>>>> 			break;
>>>>>> 		}
>>>>>> 	}
>>>>>>
>>>>>>
>>>>>> any ideas why SELinux gets confused with this, and
>>>>>> doesn't want to transistion?
>>>>>
>>>>> In the above code, you are exec'ing the shell and just passing the
>>>>> script as an argument, not exec'ing the script.  So you need a domain
>>>>> transition on the shell rather than the script, or you need to perform a
>>>>> setexecon() in the code.
>>>>>
>>>>
>>>> Thanks for the info on this..
>>>>
>>>> I'll have a look at seeing how todo this
>>>> (I enjoy the challenge).
>>>>
>>>> As an example on setexecon() I was looking
>>>> at the sulogin.c patch for SELinux, but still
>>>> need to figure out how to actually do this.
>>>
>>> Well, you can do it without using setexeccon() just by configuring
>>> policy to domain transition from init_t to initrc_t on shell_exec_t.
>>> That's what happens if you enable init_upstart=on.  So I think it is
>>> mostly just a matter of making that the default and dropping the legacy
>>> transition to sysadm_t for single-user mode.
>>>
>>
>> what/where is that code at in the policy?
>> (I've looked but can seem to grep the right word).
>
> system/init.te, line 182:
> tunable_policy(`init_upstart',`
>          corecmd_shell_domtrans(init_t, initrc_t)
> ',`
>          # Run the shell in the sysadm role for single-user mode.
>          # causes problems with upstart
>          sysadm_shell_domtrans(init_t)
> ')

ah.. I looked at this(must have bee too tired), and nothing
registered in my head.

>
>> As for the dropping the legacy(as mentioned in this post:
>> http://oss.tresys.com/pipermail/refpolicy/2010-February/002012.html)
>
> Yes, that was the prior discussion.
>

hm.. I'm thinking this should be as is i.g. if sysvinit can do
the proper things, then that's it(the policy still has legacy,
etc..)

>> tough to say... right now(as a learning experience) I'll dive into
>> sysvinit(because I need to get better at reading/writing code),
>> as well as do the same for the policy.
>

I'll look into sysv an see if I can make some headway
with it reading initscript properly.

Justin P. Mattock

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