-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Eamon Walsh wrote:
> Daniel J Walsh wrote:
>> Eamon Walsh wrote:
>>> Daniel J Walsh wrote:
>>>> I wanted to see if we could prevent nsplugin_t from screen capturing
>>>> random parts of the Desktop.
>>>>
>>>> So I relabeled /usr/bin/gimp as nsplugin_exec_t, then ran it to get
>>>> AVC's, when capturing a screen image, sadly no AVC's were generated, so
>>>> nsplugin_t can capture screen images.
>>>>
>>>> I Wanted to see what avc's are created when you screen capture that are
>>>> different from running a standard X App, so I labeled /usr/bin/gimp and
>>>> put the machine in permissive mode. Ran gimp to the point of capturing
>>>> the screen capture, and cleared the log files.
>>>>
>>>> When capturing the image I got the following allow rules.
>>>>
>>>> allow gpg_t focus_xevent_t:x_event receive;
>>>> allow gpg_t input_xevent_t:x_event receive;
>>>> allow gpg_t self:x_cursor destroy;
>>>> allow gpg_t xdm_rootwindow_t:x_drawable { read setattr };
>>>> allow gpg_t xdm_xserver_t:x_device { freeze force_cursor bell };
>>>>
>>>>
>>>> Is there anything we could eliminate from common X Apps, to prevent
>>>> nsplgugin from screen capture.
>>> It's "read" permission on the root window. Remember that if you can
>>> read a window, you can read all of its children as well. So having read
>>> on the root means you can see everything.
>>> Most apps shouldn't have this, and I don't see it granted in the current
>>> policy. Actually I think GIMP launches a helper app to actually do the
>>> screencap. I remember seeing its path in the AVC message. So maybe
>>> that's why it's not working for you.
>>
>>
>> So are you saying.
>>
>> allow gpg_t xdm_rootwindow_t:x_drawable { read setattr };
>>
>> If, I don't allow this to apps, it would be blocked?
>>
>> Or some other
>
>
> Yes, if you disallow the "read" above then it should bomb out with a
> "BadAccess" error when you try to do the screenshot.
>
>
Sadly flashplugin required this in order to watch Sarah Palin on
Saturday Night Live.
allow nsplugin_t xdm_rootwindow_t:x_drawable read;
Maybe some one is trying to take a screen capture of Sarah? :^)
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org
iEYEARECAAYFAkj84rsACgkQrlYvE4MpobPXWACfYDPg7LUgt++9hljqEIBtvx9o
Cp0AnAiMy3d5lX+G/G7TzMLGjGdr0Alg
=Wuog
-----END PGP SIGNATURE-----
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@xxxxxxxxxxxxx with
the words "unsubscribe selinux" without quotes as the message.
