gnome-shell crashed with SIGSEGV in cogl_texture_get_height(texture=0x0) from clutter_offscreen_effect_real_paint_target() from clutter_offscreen_effect_paint_texture() from clutter_offscreen_effect_paint() from clutter_actor_continue_paint()

[errors.ubuntu.com bug bridge]

[ Impact ]

Gnome shell crashes on cogl_texture_get_height

[ Test case ]

No clear reproducer is know for such issue, crashes should be monitored in e.u.c checking that this is not happening anymore for the version in proposed.

[ Regression potential ]

Low, the proposed fix is part of the current stable branch upstream and not changed in further revisions.

--

The Ubuntu Error Tracker has been receiving reports about a problem regarding gnome-shell. This problem was most recently seen with package version 3.30.0-1ubuntu2, the problem page at https://errors.ubuntu.com/problem/e5b2dcb04552882a76f1daa6b9f18ba864269d26 contains more details, including versions of packages affected, stacktrace or traceback, and individual crash reports.
If you do not have access to the Ubuntu Error Tracker and are a software developer, you can request it at http://forms.canonical.com/reports/.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Gert van de Kraats (gkraats)]

Problem can be solved at update_fbo() within clutter/clutter/clutter-offscreen-effect.c

In this case at update_fbo a texture should be alocated with width 2560 which is greater than maximal size 2048 of graphics cards.
Offscreen-effect does not support sliced textures, so this is impossible and fails.

Crash occurs because no texture is allocated but a framebuffer is present at priv->offscreen.
Code to free the framebuffer at priv->offscreen should be moved upwards at update_fbo, because it also should be executed in case texture allocation fails.
This leads to the fillowing proposed code:

  if (priv->texture != NULL)
    {
      cogl_handle_unref (priv->texture);
      priv->texture = NULL;
    }
  if (priv->offscreen != NULL)
    {
      cogl_handle_unref (priv->offscreen);
      priv->offscreen = NULL;
    }

  priv->texture =
    clutter_offscreen_effect_create_texture (self, fbo_width, fbo_height);
  if (priv->texture == NULL)
    return FALSE;

  cogl_pipeline_set_layer_texture (priv->target, 0, priv->texture);

  priv->fbo_width = fbo_width;
  priv->fbo_height = fbo_height;

  priv->offscreen = cogl_offscreen_new_to_texture (priv->texture);

Remember bug 1790525 also should be solved (which often causes an earlier crash), to make the solution complete.

[Daniel van Vugt (vanvugt)]

Thanks for that, Gert.

AFAIK mosts GPUs from the last decade support textures up to size 16384. And ideally all should at least support textures larger than the typical screen resolution they support. If your GL_MAX_TEXTURE_SIZE is 2048 then that's fairly old and uncommon. But certainly we should fix it.

My question is: what is the large actor 2560 pixels in size that the machine is trying to offscreen? It's also a performance bug (for all GPUs) if we're trying to offscreen any actor that large. Even if it doesn't crash, gnome-shell still shouldn't be doing that.

Since I am working in the area (https://gitlab.gnome.org/GNOME/mutter/merge_requests/117) the code is still fresh in my mind and I will try to implement your suggested fix. Thanks!

[Daniel van Vugt (vanvugt)]

Thanks for your efforts.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/261

[Launchpad Janitor (janitor)]

This bug was fixed in the package mutter - 3.30.2-5

---------------
mutter (3.30.2-5) unstable; urgency=medium

  * d/p/clutter-Avoid-rounding-compensation-when-invalidating-2D-.patch,
    d/p/clutter-Fix-offscreen-effect-painting-of-clones.patch:
    - Fix offscreen-effect painting of clones in zoom mode (LP: #1767648,
      LP: #1779615)
  * d/p/cogl-auto-texture-Avoid-a-double-free-crash.patch,
    d/p/clutter-offscreen-effect-Disable-if-no-texture.patch:
    - Fix crash in dual monitor setup and gdm activation (LP: #1790525,
      LP: #1795774)

 -- Marco Trevisan (Treviño) <email address hidden> Thu, 24 Jan 2019 18:00:14 +0000

[Brian Murray (brian-murray)]

Hello errors.ubuntu.com, or anyone else affected,

Accepted mutter into cosmic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/mutter/3.30.2-1~ubuntu18.10.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-cosmic to verification-done-cosmic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-cosmic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Gert van de Kraats (gkraats)]

Reinstalled current libmutter.
With dual monitor horizontal aside this problem could not be reproduced because
logon-session crashes before showing logon-screen, (caused by bug #1790525).

Installed proposed version:

apt list libmutter-3-0
Listing... Done
libmutter-3-0/cosmic-proposed,now 3.30.2-1~ubuntu18.10.3 i386 [installed]

No crash anymore when trying to suspend at logon-screen.
Problem is solved by proposed package. No new other problems detected.

[Launchpad Janitor (janitor)]

This bug was fixed in the package mutter - 3.30.2-1~ubuntu18.10.3

---------------
mutter (3.30.2-1~ubuntu18.10.3) cosmic; urgency=medium

  * d/p/clutter-Avoid-rounding-compensation-when-invalidating-2D-.patch,
    d/p/clutter-Fix-offscreen-effect-painting-of-clones.patch:
    - Fix offscreen-effect painting of clones in zoom mode (LP: #1767648,
      LP: #1779615)
  * d/p/cogl-auto-texture-Avoid-a-double-free-crash.patch,
    d/p/clutter-offscreen-effect-Disable-if-no-texture.patch:
    - Fix crash in dual monitor setup and gdm activation (LP: #1790525,
      LP: #1795774)

 -- Marco Trevisan (Treviño) <email address hidden> Fri, 25 Jan 2019 11:09:33 +0000

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for mutter has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Łukasz Zemczak (sil2100)]

Hello errors.ubuntu.com, or anyone else affected,

Accepted mutter into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/mutter/3.28.3+git20190124-0ubuntu18.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Gert van de Kraats (gkraats)]

Verification succeeded. Problem solved

[Łukasz Zemczak (sil2100)]

Hello errors.ubuntu.com, or anyone else affected,

Accepted mutter into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/mutter/3.28.3+git20190124-0ubuntu18.04.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Gert van de Kraats (gkraats)]

Problem could not be reproduced, because it was hidden by bug #1795774.

After installation from proposed, the problem was solved:

root@gert-laptop:/etc/apt# dpkg -s libmutter-2-0 | grep Version
Version: 3.28.3+git20190124-0ubuntu18.04.2

[Gert van de Kraats (gkraats)]

I did at #14 again, set verification-done-bionic for this fix, as requested.
Again it disappears.
I now tested the fix 3 times (once for cosmic and twice for bionic).
This time I did the same test as at #8.
Whatever you do it was the last time I test this bug.

[Launchpad Janitor (janitor)]

This bug was fixed in the package mutter - 3.28.3+git20190124-0ubuntu18.04.2

---------------
mutter (3.28.3+git20190124-0ubuntu18.04.2) bionic; urgency=medium

  * control: Add Breaks on budgie-desktop verions broken by this upload.
    budgie-desktop needs a fix in 10.4+git20171031.10.g9f71bb8-1.2ubuntu1.2
    for compatibility with this mutter.

mutter (3.28.3+git20190124-0ubuntu18.04.1) bionic; urgency=medium

  * New upstream git snapshot based on 3.28.3 plus commits up to 4af8d9d47
    (LP: #1811900)
    - Fix crash in dual monitor setup and gdm activation (LP: #1790525,
      LP: #1795774)
    - Make possible to launch gnome-shell in wayland using nvidia and EGLDevice
      backend (LP: #1805444)
  * debian/libmutter-2-0.symbols: Add new symbols
  * d/p/gpu-kms-Don-t-crash-if-drmModeGetResources-returns-N.patch,
    d/p/native-gpu-Handle-drmModeSetCrtc-failing-gracefully.patch,
    d/p/monitor-manager-Filter-out-low-screen-resolutions.patch,
    d/p/window-wayland-Always-update-monitor-for-non-user-ops.patch,
    d/p/window-Don-t-refuse-to-move-focus-to-the-grab-window.patch,
    d/p/window-Explicitly-exclude-unmanaging-window-from-focus-ag.patch,
    d/p/monitor-Use-current-monitor-mode-to-check-whether-active.patch,
    d/p/core-Return-1-if-meta_window_get_monitor-is-called-on-an-.patch,
    d/p/renderer-native-Fallback-to-non-planar-API-if-gbm_bo_get_.patch,
    d/p/clutter-x11-Implement-keycode-lookup-from-keysyms-on-virt.patch,
    d/p/clutter-Do-not-latch-modifiers-on-modifier-keys.patch:
    - Removed as applied upstream
  * d/p/clutter-Fix-offscreen-effect-painting-of-clones.patch:
    - Fix offscreen-effect painting of clones in zoom mode (LP: #1767648,
      LP: #1779615)

 -- Iain Lane <email address hidden> Wed, 17 Apr 2019 11:35:51 +0100