Bug#1151665: mutter: gnome-shell segfaults with NVIDIA 550 after upgrade to 51.0-3

[Jeremy Bícha]

Control: affects -1 src:nvidia-graphics-drivers

On Thu, Oct 22, 2026 at 9:01 PM Claudio Giordano
<claudiogiordano at disroot.org> wrote:
>
> Package: mutter
> Version: 51.0-3
> Severity: serious
>
> Dear maintainers,
>
> after upgrading mutter and gnome-shell to 51.0-3 (Debian sid, 2026-10-22),
> GDM can no longer start a greeter and the GNOME session crashes at startup
> on a system using the proprietary NVIDIA driver shipped in testing/sid
> (550.163.01-5.1).
>
> Symptoms
>
> - gdm retries until "GdmLocalDisplayFactory: maximum number of display
>   failures reached. Giving up."
> - gnome-shell[3916]: segfault at ... ip ... sp ... error 4 in
>   libmutter-cogl-51.so.0.0.0[5faf4]
> - org.gnome.Shell at gdm.service: Main process exited, code=killed,
>   status=11/SEGV
> - GdmDisplay: Session never registered, failing
>
> Reproduction (deterministic, without GDM)
>
>   $ gnome-shell --headless --mode=user; echo $?
>   139
>   $ gnome-shell --headless --mode=gdm; echo $?
>   139
>
> strace shows the NVIDIA EGL/GBM stack being loaded (renderD129,
> nvidia-drm_gbm.so, libEGL_nvidia.so) followed by SIGSEGV. The faulting
> offset 0x5faf4 corresponds to cogl_renderer_is_hardware_accelerated(),
> which dereferences a NULL renderer. Upstream mutter 51 removed support for
> legacy NVIDIA drivers (NEWS 51.alpha, MR !5079); whether 550 counts as
> legacy is unclear, but mutter should not segfault when renderer/EGL
> initialization fails.
>
> System
>
> - Debian sid/testing (forky), kernel 7.1.13+deb14-amd64
> - mutter 51.0-3, gnome-shell 51.0-3, gdm3 51.1-1
> - nvidia-driver 550.163.01-5.1, GeForce RTX 3070 Ti Laptop GPU
> - Downgrading mutter/gnome-shell to 50.5-1 (testing) makes GNOME work again
>
> Impact
>
> 550.163.01 is the newest nvidia-driver in testing and sid; 555.58.02 has
> been in experimental since 2024. When mutter 51 migrates to testing, GNOME
> will be unusable for users of the packaged NVIDIA driver.
>
> Please consider:
>
> 1. keeping mutter 51 out of testing until a compatible driver is
>    available, or
> 2. adding a versioned Breaks/Conflicts against nvidia-driver (<< 555) so
>    apt cannot install the broken combination, and/or
> 3. fixing the NULL dereference so an EGL failure degrades gracefully
>    instead of killing gnome-shell.
>
> Thanks,
> Claudio Giordano

Did you try the nvidia drivers from Experimental?

Thank you,
Jeremy Bícha