Mac OS X 10.8 Mountain Lion Untrusted DL Driver

[tawman]

Based on a comment by a DisplayLink representative that the driver relies on the Mac OS X Lion launcher, I realized the DisplayLink driver is probably not trusted by OS X. A new "feature" of OS X 10.8 is that software and drivers are sandboxed and applications not signed or installed from the app store are limited.

I decided to uninstall / install the 1.8 driver after turning off the new Mac OS X 10.8 trusted drivers settings that are enabled by default. I noticed an immediate difference in how windows / fonts / positioning of windows on the DL monitor react. I have only done this 15 minutes ago so will take rest of day to know for sure.

I searched through my old system logs for when the security settings were on the default "Mac App Store and identified developers" and found references to instances when the OS did not trust the driver:


Aug 10 08:06:39 kvothe.local WindowServer[120]: post_notification : Time out waiting for reply from "DisplayLinkUserAgent" for notification type 109 (CID 0x119ef, PID 252)
Aug 10 08:06:39 kvothe.local DisplayLinkManager[17419]: SCNetworkReachabilityCreateWithAddress[Pair] called with invalid address family 1
Aug 10 08:09:54 kvothe.local DisplayLinkUserAgent[136]: SCNetworkReachabilityCreateWithAddress[Pair] called with invalid address family 1
Aug 10 08:09:58 kvothe.local DisplayLinkManager[140]: 3891612: (connect_and_check) Untrusted apps are not allowed to connect to or launch Window Server before login.
Aug 10 08:09:58 kvothe.local DisplayLinkManager[140]: kCGErrorFailure: This user is not allowed access to the window system right now.
Aug 10 08:09:58 kvothe.local DisplayLinkManager[140]: CGSGetDisplayBounds: Invalid display 0x00000000
Aug 10 08:09:58 kvothe.local DisplayLinkManager[140]: _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
Aug 10 08:09:58 kvothe.local DisplayLinkManager[140]: kCGErrorInvalidConnection: CGSGetEventPort: Invalid connection
Aug 10 08:09:58 kvothe.local DisplayLinkManager[140]: CGSRegisterConnectionNotifyProc called with invalid connection
Aug 10 08:09:58 kvothe.local DisplayLinkManager[140]: SCNetworkReachabilityCreateWithAddress[Pair] called with invalid address family 1
Aug 10 08:11:05 kvothe.local DisplayLinkUserAgent[269]: SCNetworkReachabilityCreateWithAddress[Pair] called with invalid address family 1
Aug 10 08:11:53 kvothe.local DisplayLinkManager[322]: SCNetworkReachabilityCreateWithAddress[Pair] called with invalid address family 1

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Compare this to the log from when I first connected the same display after disabling the security settings:

8/17/12 9:04:37.175 AM DisplayLinkUserAgent[319]: SCNetworkReachabilityCreateWithAddress[Pair] called with invalid address family 1
8/17/12 9:07:46.038 AM DisplayLinkManager[570]: SCNetworkReachabilityCreateWithAddress[Pair] called with invalid address family 1

[Carlo]

Thank you for the report, we'll look into it in detail.

Carlo

[gkra]

FYI, getting the same problem on 10.7.4, which, when I go to the login screen any time after connecting a DisplayLink device, the system beachballs and I cannot log on anymore, to the point that I have to hard-power off the Mac and reboot it.

9/21/12 2:47:37.439 PM DisplayLinkManager: 3891612: (connectAndCheck) Untrusted apps are not allowed to connect to or launch Window Server before login.
9/21/12 2:47:37.439 PM DisplayLinkManager: kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged.
9/21/12 2:47:37.476 PM DisplayLinkManager: _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
9/21/12 2:47:37.476 PM com.displaylink.usbnivolistener: _RegisterApplication(), FAILED TO establish the default connection to the WindowServer, _CGSDefaultConnection() is NULL.
9/21/12 2:47:37.479 PM DisplayLinkManager: SCNetworkReachabilityCreateWithAddress[Pair] called with invalid address family 1

[gkra]

So, some more details. The log errors only show up if I'm logged in, and use the Fast User Switching menu to go to the login window. At that point, the login window shows up on the primary display with the background on the secondary (DisplayLink-connected) display, and the system immediately beachballs.

If I log out, the system is okay.
If I activate the screen saver, the system is okay.

This only happens after I connect the DisplayLink device. However, even after I disconnect the DisplayLink device, the behavior remains. I haven't found any way to recover from the beachball-on-login-window problem aside from a hard power off, which I'm none to keen on.

Reading up on the error messages, I thought it might be related to latent Gatekeeper interactions, as Gatekeeper has been present since 10.7.3 in a disabled state. I applied the available system updates to 10.7.5, and verified that Gatekeeper is disabled (allow anything to run), and the problem remains.

Initial problems were present with both DisplayLink driver versions 1.7 and 1.8 on OS X 10.7.4. Problems are also present with both 1.7 and 1.8 versions on OS X 10.7.5.

I've currently uninstalled the drivers as I'm planning on updating to OS X 10.8.2 this weekend (for other reasons) and will re-install them when I'm back at my desk Monday morning.

[Carlo]

I'm re-readig these posts and I have a doubt: which Gatekeeper settings have you exactly chosen?
Our driver can't be trusted in the most tight settings because no kernel extension can be installed from the App Store, so that would be expected.

Carlo

[gkra]

I'm re-readig these posts and I have a doubt: which Gatekeeper settings have you exactly chosen?
Our driver can't be trusted in the most tight settings because no kernel extension can be installed from the App Store, so that would be expected.

Carlo

Well, the thing that was confusing the heck out of me is that I was getting these errors with the v1.8 drivers on Lion 10.7.4. Apparently Gatekeeper is present-but-hidden/disabled as of 10.7.3. I've used Software Update to get to 10.7.5, which added Gatekeeper settings to the Security Preference Pane, but in my case, it's all disabled. I.e., "run anything".

On my Mac, the only time this happens is if, once logged in, I select "Login Window" from the Fast User Switching menu bar item. The messages are logged to the system logs, and then the mouse pointer goes to a beach ball, the fans spin up, and the only way to recover the system is via a power-off reboot.

I've tried all other things I can think of, but that's the only thing that causes the bad behavior.

I haven't gotten around to upgrading to Mountain Lion yet, and can likely hold off if you need me to test anything.