[Bug 2172423] Re: Regression 7.0.0-42/-43: Go 1.24 programs livelock in setuid (gosu); official DB Docker images hang on start

Installed kernel packages (-38 working, -42 and -43 broken) and uname -a from the running -38 kernel. ** Attachment added: "kernels-installed.log" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2172423/+attachment/6013235/+files/kernels-installed.log -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2172423 Title: Regression 7.0.0-42/-43: Go 1.24 programs livelock in setuid (gosu); official DB Docker images hang on start Status in linux package in Ubuntu: New Bug description: Summary ------- After upgrading from 7.0.0-38 to 7.0.0-42 (resolute-updates, published 2026-10-28), gosu 1.19 (built with Go 1.24.6) never returns. The official mariadb, postgres and mongo Docker images use gosu to drop privileges in their entrypoints, so all of those containers hang at "Switching to dedicated user" indefinitely. 7.0.0-43 from -proposed shows the same behavior. Booting back to 7.0.0-38 fixes it immediately. Reproducer ---------- timeout 60 docker run --rm --entrypoint gosu mariadb:10.11 nobody id 7.0.0-38: prints "uid=65534(nobody) gid=65534(nogroup) ..." instantly 7.0.0-42: hangs until the timeout 7.0.0-43: hangs until the timeout On -42 and -43 this was tested at 10+ minutes of uptime, after the boot-time load had settled. Stuck gosu processes were still alive after 270+ seconds. On -42 the host stayed in this state for ~10 hours (database containers restarted ~180 times each, never starting). Observations ------------ - strace -f of a stuck gosu process (6 threads): main thread: sched_yield() = 0, repeated forever other 5: futex(..., FUTEX_WAIT_PRIVATE, 0, NULL) (never woken) This looks like Go's all-threads setuid/setgid path (runtime.doAllThreadsSyscall) waiting forever for threads that are never woken or signaled. - gosu 1.13 built with Go 1.16.5 (image mariadb:10.6.4-focal) WORKS on 7.0.0-43. Only the newer Go runtime (1.24.6) is affected. - Same host, same images; only the kernel changed. The same images work on other hosts running 7.0.0-38. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2172423/+subscriptions