Public bug reported: Ubuntu release: 26.04 LTS (Resolute Raccoon) Firefox snap version: 1:1snap1-0ubuntu8 (transitional wrapper to snap)
Expected: RDD process memory stays bounded Actual: shmem-rss grows to ~28GB, triggers OOM, system freezes The Firefox RDD (Remote Data Decoder) process running under snap confinement accumulates shared memory (shmem-rss) over time during normal browsing. On a 32GB system the process reached ~28GB shmem-rss within ~40 minutes of use, triggered global OOM, and the system became unresponsive to all input including Alt+SysRq before recovery. Native Firefox (.deb from packages.mozilla.org) does not reproduce this on identical hardware and workload. Steps to reproduce: 1. Fresh install of Ubuntu 26.04 with default snap Firefox 2. NVIDIA proprietary driver + Wayland session 3. Browse normally over ~40 minutes, including video content (YouTube) Expected: RDD process memory stays bounded; shared memory buffers released. Actual: shmem-rss grows without bound. After ~40 minutes, ~28GB consumed by the RDD process alone. System enters severe memory pressure, becomes fully unresponsive (mouse cursor frozen, no keyboard input). Magic SysRq (REISUB) does not respond. Recovery requires hard power-off. The freeze was severe enough that the kernel logged 14 power-button presses over 4 seconds (15:40:28-32) but couldn't act on them. OOM-kill finally fired 26 seconds later at 15:40:58. Relevant log excerpt: oom-kill: constraint=CONSTRAINT_NONE, task_memcg=/user.slice/user-1000.slice/[email protected]/app.slice/ snap.firefox.firefox-08265f4a-c476-4c59-8a60-c6a4d07983b9.scope, task=RDD Process, pid=7813 Out of memory: Killed process 7813 (RDD Process) total-vm:36615980kB, anon-rss:93128kB, file-rss:8kB, shmem-rss:28213668kB, pgtables:70744kB oom_reaper: reaped process 7813 (RDD Process), now anon-rss:0kB, file-rss:0kB, shmem-rss:28081524kB Note: shmem-rss remains at 28GB even after OOM-kill and reap. The kernel cannot reclaim shared memory held across the snap cgroup boundary. systemd attributes the leak to the snap scope: snap.firefox.firefox-...scope: Consumed 10min 30.546s CPU time over 39min 1.157s wall clock time, 27.8G memory peak, 7.7G memory swap peak. System: - Ubuntu 26.04 LTS - Kernel: 7.0.0-15-generic - Firefox snap, channel latest/stable - GNOME 50.1, Wayland session - NVIDIA driver 595.58.03 (nvidia-driver-595-open at time of incident) - GPU: GeForce RTX 2070 Super - CPU: Ryzen 9 3900X - RAM: 32GB ~$ lsb_release -rd Description: Ubuntu 26.04 LTS Release: 26.04 Workaround: Replaced snap Firefox with .deb from packages.mozilla.org. With comparable workload (20+ tabs, video content) shmem-rss remains stable. Full logs (OOM dump, memory events from freeze boot, last 5 minutes before lock-up): https://gist.github.com/KnuTNatioN/a87405a9a1bf68bad0509e4a677b6afd Reddit thread with additional discussion (10k+ views, similar reports with Brave snap): https://www.reddit.com/r/Ubuntu/comments/1tf0osh/ ** Affects: firefox (Ubuntu) Importance: Undecided Status: New ** Tags: firefox gnome memory-leak nvidia oom snap wayland ** Attachment added: "snap-firefox-oom-logs.txt" https://bugs.launchpad.net/bugs/2152836/+attachment/5970992/+files/snap-firefox-oom-logs.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2152836 Title: Snap Firefox RDD process leaks shmem-rss until OOM, system freeze with SysRq unresponsive To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/2152836/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
