Package: libmutter-16-0 Version: 48.7-0+deb13u1 Severity: important Tags: upstream fixed-upstream Forwarded: https://gitlab.gnome.org/GNOME/mutter/-/issues/4101
Dear maintainers, On trixie, gnome-shell leaks GPU buffers while the session is locked and the external monitor is in power saving. GTT fills to its ceiling, overflows into unmapped shmem and swap, and the kernel OOM killer then kills small unrelated processes, which frees nothing. Four episodes here in six days. This matches upstream issue 4101. Please consider backporting the fix to trixie. System: ThinkPad P14s Gen 2a, Ryzen 7 PRO 5850U (integrated Radeon), 32 GiB, kernel 6.12.86+deb13-amd64, mesa 25.0.7-2+deb13u1, gnome-shell 48.7-0+deb13u2, mutter 48.7-0+deb13u1, Wayland. Internal panel plus ASUS PA278QV connected via USB-C dock, DisplayPort. Evidence (mem_info_gtt_used, /proc/meminfo, fdinfo drm-memory-gtt): 2026-09-20 22:10: gtt_used 16183771136 of 16208060416, gnome-shell alone 15362 MiB, Shmem 12.2 GiB with /dev/shm and memfds empty, MemAvailable 64 MB. OOM kills 21:59 to 22:37. At about 22:37 all of it was released at once, same gnome-shell PID. Reproduction, 2026-09-21: Super+L, monitor sleeps, 15 minutes. gtt_used 240 MiB before, 5299834880 while locked, 1611337728 five minutes after unlock. Control: monitor switched off at its power button, then the same lock. gtt_used flat at about 530 MB. No leak. Fix: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/5285 ("renderer/native: Don't keep around detached onscreens in power saving"), merged 2026-09-03, in gnome-50 via !5325, released in 50.5. Launchpad bug 2167374 says the backport needs two companion commits (83c465ff, c145106d) and should not be taken without them. I have not verified those hashes. Workaround: switch the external monitor off before locking. Thanks, Philippe Baret -- System Information: Debian Release: 13.7 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 6.12.86+deb13-amd64 (SMP w/16 CPU threads; PREEMPT) Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages libmutter-16-0 depends on: ii adwaita-icon-theme 48.1-1 ii gsettings-desktop-schemas 48.0-1 ii libatk1.0-0t64 2.56.2-1+deb13u2 ii libc6 2.41-12+deb13u4 ii libcairo2 1.18.4-1+b1 ii libcanberra0 0.30-18 ii libcolord2 1.4.7-3 ii libdisplay-info2 0.2.0-2 ii libdrm2 2.4.124-2 ii libegl1 1.7.0-1+b2 ii libeis1 1.3.901-1 ii libfribidi0 1.0.16-1 ii libgbm1 25.0.7-2+deb13u1 ii libgdk-pixbuf-2.0-0 2.42.12+dfsg-4+deb13u1 ii libgl1 1.7.0-1+b2 ii libglib2.0-0t64 2.84.4-3~deb13u5 ii libgnome-desktop-4-2t64 44.3-3 ii libgraphene-1.0-0 1.10.8-5 ii libgudev-1.0-0 238-6 ii libharfbuzz0b 10.2.0-1+deb13u1 ii libice6 2:1.1.1-1 ii libinput10 1.28.1-1+deb13u1 ii liblcms2-2 2.16-2+deb13u2 ii libpango-1.0-0 1.56.3-1 ii libpangocairo-1.0-0 1.56.3-1 ii libpipewire-0.3-0t64 1.4.2-1 ii libpixman-1-0 0.44.0-3 ii libsm6 2:1.2.6-1 ii libstartup-notification0 0.12-8 ii libsystemd0 257.13-1~deb13u1 ii libudev1 257.13-1~deb13u1 ii libwacom9 2.14.0-1 ii libwayland-server0 1.23.1-3 ii libx11-6 2:1.8.12-1 ii libx11-xcb1 2:1.8.12-1 ii libxau6 1:1.0.11-1 ii libxcb-randr0 1.17.0-2+b1 ii libxcb-res0 1.17.0-2+b1 ii libxcb1 1.17.0-2+b1 ii libxcomposite1 1:0.4.6-1 ii libxcursor1 1:1.2.3-1 ii libxdamage1 1:1.1.6-1+b2 ii libxext6 2:1.3.4-1+b3 ii libxfixes3 1:6.0.0-2+b4 ii libxi6 2:1.8.2-1 ii libxinerama1 2:1.1.4-3+b4 ii libxkbcommon-x11-0 1.7.0-2 ii libxkbcommon0 1.7.0-2 ii libxkbfile1 1:1.1.0-1+b4 ii libxrandr2 2:1.5.4-1+b3 ii libxtst6 2:1.2.5-1 ii mutter-common 48.7-0+deb13u1 ii mutter-common-bin 48.7-0+deb13u1 libmutter-16-0 recommends no packages. libmutter-16-0 suggests no packages. Versions of packages libmutter-16-0 is related to: ii libegl-mesa0 [libegl-vendor] 25.0.7-2+deb13u1 ii libgl1-mesa-dri 25.0.7-2+deb13u1 ii libglx-mesa0 [libglx-vendor] 25.0.7-2+deb13u1 -- no debconf information<br/>
