Re: Tonights rawhide contains a fix to stop xspy.

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Daniel J Walsh wrote:
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Basically if you turn on xserver_object_manager boolean, no applications
will be allowed to read the x_device.  This stops xspy as you said dead
in its tracks,  but some other applications start to get AVC's around
querypointer, and eventually I hung the server.  You mentioned in
another email, that you were going to change the querypointer to a
getattr rather then a read, I think this is necessary, to make this work.

I have attached a patch that will do this. There is another request, XKEYBOARD:GetState, that also requires read and I've noticed that gnome-settings-daemon is calling it (see below). If you want to drop that down to getattr too, let me know; it doesn't look like it returns the whole keyboard like XQueryKeymap does, however both it and XQueryPointer return the mouse buttons and the modifier keys (shift, alt, ctrl, etc.). Long-term we really need to get applications to stop calling these.

"Manage" permission on devices is another can of worms you may care to open at some point. Anyone with that can remap the keys or do other things that affect the device globally.

The other AVC's I'm getting are from interactions between staff_mono and staff. I believe that this the result of a small application such as the clock or load graph being staff_mono_t, running inside gnome-panel which is staff_t. This is the type of thing I was trying to solve with the 4-argument templates that allowed some permissions among the entire "role's" windows (however manage was not one of them).

avc:  denied  { use } for request=XTEST:GrabControl comm=/usr/libexec/at-spi-registryd extension=XTEST scontext=staff_u:staff_r:staff_t:s0 tcontext=system_u:object_r:debug_xext_t:s0 tclass=x_extension
avc:  denied  { read } for request=XKEYBOARD:GetState comm=/usr/libexec/gnome-settings-daemon xdevice="Virtual core keyboard" scontext=staff_u:staff_r:staff_t:s0 tcontext=system_u:system_r:xdm_xserver_t:s0-s0:c0.c1023 tclass=x_device
avc:  denied  { manage } for request=XKEYBOARD:SetMap comm=/usr/libexec/gnome-settings-daemon xdevice="Virtual core keyboard" scontext=staff_u:staff_r:staff_t:s0 tcontext=system_u:system_r:xdm_xserver_t:s0-s0:c0.c1023 tclass=x_device
avc:  denied  { use } for request=RANDR:GetScreenSizeRange comm=/usr/libexec/gnome-settings-daemon extension=RANDR scontext=staff_u:staff_r:staff_t:s0 tcontext=system_u:object_r:output_xext_t:s0 tclass=x_extension
avc:  denied  { receive } for request=X11:ChangeWindowAttributes comm=mono resid=1400006 restype=WINDOW scontext=staff_u:staff_r:staff_mono_t:s0 tcontext=staff_u:object_r:staff_t:s0 tclass=x_drawable
avc:  denied  { getattr } for request=X11:GetWindowAttributes comm=mono resid=1400006 restype=WINDOW scontext=staff_u:staff_r:staff_mono_t:s0 tcontext=staff_u:object_r:staff_t:s0 tclass=x_drawable
avc:  denied  { list_child } for request=X11:QueryTree comm=mono resid=1400006 restype=WINDOW scontext=staff_u:staff_r:staff_mono_t:s0 tcontext=staff_u:object_r:staff_t:s0 tclass=x_drawable
avc:  denied  { get_property } for request=X11:GetProperty comm=mono resid=1400006 restype=WINDOW scontext=staff_u:staff_r:staff_mono_t:s0 tcontext=staff_u:object_r:staff_t:s0 tclass=x_drawable
avc:  denied  { read } for request=X11:GetProperty comm=mono property=_XSETTINGS_SETTINGS scontext=staff_u:staff_r:staff_mono_t:s0 tcontext=staff_u:object_r:staff_default_xproperty_t:s0 tclass=x_property
avc:  denied  { list_child } for request=X11:QueryTree comm=gnome-screensaver resid=4e00001 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { get_property } for request=X11:GetProperty comm=/usr/libexec/gnome-settings-daemon resid=4e00001 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { read } for request=X11:GetProperty comm=/usr/libexec/gnome-settings-daemon property=WM_NAME scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_default_xproperty_t:s0 tclass=x_property
avc:  denied  { getattr } for request=X11:GetWindowAttributes comm=gnome-screensaver resid=4e00001 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { receive } for request=X11:ChangeWindowAttributes comm=gnome-screensaver resid=4e00001 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { receive } for  comm=/usr/libexec/gnome-settings-daemon event=X11:PropertyNotify scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_property_xevent_t:s0 tclass=x_event
avc:  denied  { receive } for  comm=/usr/libexec/gnome-settings-daemon event=X11:CreateNotify scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_manage_xevent_t:s0 tclass=x_event
avc:  denied  { hide } for request=X11:UnmapWindow comm=gnome-panel resid=4e00021 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { manage } for request=X11:ReparentWindow comm=gnome-panel resid=4e00021 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { send } for request=X11:SendEvent comm=gnome-panel resid=4e00021 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { send } for request=X11:SendEvent comm=gnome-panel event=X11:ClientMessage scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_client_xevent_t:s0 tclass=x_synthetic_event
avc:  denied  { setattr } for request=X11:ConfigureWindow comm=gnome-panel resid=4e00021 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { set_property } for request=X11:ChangeProperty comm=gnome-panel resid=4e00021 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { show } for request=X11:MapWindow comm=gnome-panel resid=4e00021 restype=WINDOW scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_t:s0 tclass=x_drawable
avc:  denied  { receive } for  comm=gnome-screensaver event=X11:Expose scontext=staff_u:staff_r:staff_t:s0 tcontext=staff_u:object_r:staff_mono_default_xevent_t:s0 tclass=x_event
avc:  denied  { use } for request=GLX:QueryVersion comm=/usr/libexec/gnome-screensaver-gl-helper extension=GLX scontext=staff_u:staff_r:staff_t:s0 tcontext=system_u:object_r:accelgraphics_xext_t:s0 tclass=x_extension




#============= mono_t ==============
allow mono_t xdm_xserver_t:x_device read;

#============= unconfined_t ==============
allow unconfined_t xdm_xserver_t:x_device read;

#============= xdm_t ==============
allow xdm_t xdm_xserver_t:x_device read;

type=USER_AVC msg=audit(1204170576.402:774): user pid=2729 uid=0
auid=4294967295 subj=system_u:system_r:xdm_xserver_t:s0-s0:c0.c1023
msg='avc:  denied  { read } for request=X11:QueryPointer comm=mono
xdevice="Virtual core pointer"
scontext=unconfined_u:unconfined_r:mono_t:s0
tcontext=system_u:system_r:xdm_xserver_t:s0-s0:c0.c1023 tclass=x_device
: exe="/usr/bin/Xorg" (sauid=0, hostname=?, addr=?, terminal=?)'
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--
Eamon Walsh <ewalsh@xxxxxxxxxxxxx>
National Security Agency

>From 4632ea22580c31d44b0786321668d9e78f02900e Tue Feb 26 22:00:52 2008
From: Eamon Walsh <ewalsh@xxxxxxxxxxxxx>
Date:   Tue Feb 26 22:00:52 2008 -0500
Subject: getattr exception for XQueryPointer

---
diff --git a/Xext/xselinux.c b/Xext/xselinux.c
index 98e1ec5..e983626 100644
--- a/Xext/xselinux.c
+++ b/Xext/xselinux.c
@@ -531,6 +531,16 @@ SELinuxDevice(CallbackListPtr *pcbl, pointer unused, pointer calldata)
 	dsubj->sid = subj->sid;
     }
 
+    /* XXX Exception for XQueryPointer */
+    if (rec->client->index) {
+	ClientPtr client = rec->client;
+	REQUEST(xReq);
+	if (stuff && stuff->reqType == X_QueryPointer) {
+	    rec->access_mode |= DixGetAttrAccess;
+	    rec->access_mode &= ~DixReadAccess;
+	}	
+    }
+    
     rc = SELinuxDoCheck(subj, obj, SECCLASS_X_DEVICE, rec->access_mode,
 			&auditdata);
     if (rc != Success)

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