Package: libc6 Version: 2.28-10 Severity: important Dear Maintainer,
In short, this bug causes condition variable signal (pthread_cond_signal) to be missed by condition variable waiters (pthread_cond_wait) in some circumstances. Bug is introduced in glibc 2.27. There are few patches to fix this issue, none of them merged at this time. This bug was reported in great details here: https://sourceware.org/bugzilla/show_bug.cgi?id=25847 How to reproduce: use the repro from the sourceware report I confirm that using the repro from sourceware report I was able to reproduce issue on several Debian 10 machines. In my case It takes from 20 minutes to few hours to make repro hang. On other hand I was not able to reproduce issue on Debian 9 machine running repro for 20+ hours. This bug is also mentioned here: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1899800 https://bugzilla.redhat.com/show_bug.cgi?id=1889892 https://discuss.ocaml.org/t/is-there-a-known-recent-linux-locking-bug-that-affects-the-ocaml-runtime/6542 https://jira.mongodb.org/browse/SERVER-47554 https://probablydance.com/2020/10/31/using-tla-in-the-real-world-to-understand-a-glibc-bug/ -- System Information: Debian Release: 10.8 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 4.19.0-14-amd64 (SMP w/16 CPU cores) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages libc6 depends on: ii libgcc1 1:8.3.0-6 Versions of packages libc6 recommends: ii libidn2-0 2.0.5-1+deb10u1 Versions of packages libc6 suggests: ii debconf [debconf-2.0] 1.5.71 pn glibc-doc <none> ii libc-l10n 2.28-10 ii locales 2.28-10 -- debconf information: glibc/kernel-not-supported: glibc/restart-failed: glibc/upgrade: true libraries/restart-without-asking: false glibc/restart-services: glibc/disable-screensaver: glibc/kernel-too-old:
