Patch for glibc Bug 23538 - "Hang in pthread_cond_broadcast" not available on Ubuntu LTS

Bug #1858203 reported by Martin Unzner
20
This bug affects 3 people
Affects Status Importance Assigned to Milestone
glibc (Ubuntu)
Fix Released
Undecided
Unassigned
Bionic
Fix Released
High
Unassigned

Bug Description

[Impact]
 * Glibc can hang when using pthread condition variables

[Test Case]
* Not provided, thus observe the upstream patch being applied while building the package:

commit 2b47bb9cba048e778a7d832f284feccb14a40483
Author: Martin Kuchta <email address hidden>
Date: Mon Aug 27 18:54:46 2018 +0200

    pthread_cond_broadcast: Fix waiters-after-spinning case [BZ #23538]

    (cherry picked from commit 99ea93ca31795469d2a1f1570f17a5c39c2eb7e2)

[Regression Potential]
* Can cause incorrect sinchronization across threads leading various stability and correctness problems, but the fix is small and is part of the upstream branch for some time. Also extensive regression testing was performed to detect regressions.

[Original Bug Text]
There is a patch for versions of glibc prior to 2.29 which fixes a hang that can occur when using pthread condition variables. [1]

I was unable to locate the patch [2] in the glibc-source tree. However, I can confirm that the defect also occurs on Ubuntu 18.04 with glibc 2.27-3.

Would it be possible to backport the patch to the glibc version shipped with the current LTS of Ubuntu?

Thanks!

Martin

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=23538
[2] https://sourceware.org/ml/libc-alpha/2018-08/msg00513.html

CVE References

Revision history for this message
Gregor Jasny (gjasny) wrote :
Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in glibc (Ubuntu):
status: New → Confirmed
tags: added: bionic rls-bb-incoming
Changed in glibc (Ubuntu Bionic):
status: New → Confirmed
importance: Undecided → High
tags: added: id-5e20a12ae93db717a02ad190
tags: removed: rls-bb-incoming
Revision history for this message
Balint Reczey (rbalint) wrote :

Fixed in Ubuntu 19.04 and later.

Changed in glibc (Ubuntu):
status: Confirmed → Fix Released
Balint Reczey (rbalint)
description: updated
description: updated
Revision history for this message
Steve Langasek (vorlon) wrote : Please test proposed package

Hello Martin, or anyone else affected,

Accepted glibc into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/glibc/2.27-3ubuntu1.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Changed in glibc (Ubuntu Bionic):
status: Confirmed → Fix Committed
tags: added: verification-needed verification-needed-bionic
Revision history for this message
Ubuntu SRU Bot (ubuntu-sru-bot) wrote : Autopkgtest regression report (glibc/2.27-3ubuntu1.3)
Download full text (6.9 KiB)

All autopkgtests for the newly accepted glibc (2.27-3ubuntu1.3) for bionic have finished running.
The following regressions have been reported in tests triggered by the package:

mysql-5.7/5.7.31-0ubuntu0.18.04.1 (armhf)
libsys-utmp-perl/1.8-1 (armhf)
libscope-upper-perl/0.30-1 (armhf)
octave-miscellaneous/1.2.1-4 (armhf, arm64, s390x, amd64, i386, ppc64el)
libsocket-multicast6-perl/unknown (armhf)
octave-strings/1.2.0-3 (armhf, arm64, s390x, amd64, i386, ppc64el)
libgnatcoll/unknown (armhf)
octave-econometrics/1:1.1.1-5 (armhf, arm64, s390x, amd64, i386, ppc64el)
octave-secs2d/0.0.8-9 (armhf, arm64, s390x, amd64, i386, ppc64el)
libb-hooks-parser-perl/unknown (armhf)
octave-general/2.0.0-3 (armhf, arm64, s390x, amd64, i386, ppc64el)
libcompress-raw-bzip2-perl/2.074-1build2 (armhf)
libunicode-casefold-perl/unknown (armhf)
mod-wsgi/4.5.17-1ubuntu1 (ppc64el)
libdata-alias-perl/unknown (armhf)
libdata-clone-perl/unknown (armhf)
libsort-key-perl/unknown (armhf)
linux-raspi-5.4/5.4.0-1018.20~18.04.1 (armhf)
ann/unknown (armhf)
icecast2/unknown (i386)
python-maxminddb/1.3.0-1 (armhf)
lua-torch-sundown/unknown (armhf)
libkf5mailcommon/4:17.12.3-0ubuntu1 (arm64, i386)
apport/2.20.9-0ubuntu7.17 (amd64)
linux-hwe-5.0/5.0.0-61.65 (armhf)
ffmpeg/7:3.4.8-0ubuntu0.2 (armhf, arm64, s390x, amd64, i386, ppc64el)
glibc/2.27-3ubuntu1.3 (armhf)
nut/2.7.4-5.1ubuntu2 (amd64)
mbuffer/unknown (armhf)
linux-aws-edge/5.0.0-1019.21~18.04.1 (amd64, arm64)
octave-ocs/0.1.5-6 (armhf, arm64, s390x, amd64, i386, ppc64el)
libx11-xcb-perl/unknown (armhf)
pgbouncer/1.8.1-1build1 (amd64)
indicator-session/17.3.20+17.10.20171006-0ubuntu1 (armhf)
gcc-6/6.5.0-2ubuntu1~18.04 (armhf)
vmtouch/unknown (armhf)
libhtml-gumbo-perl/0.17-1build1 (ppc64el)
octave-sparsersb/1.0.5-3 (armhf, arm64, s390x, amd64, i386, ppc64el)
octave-mpi/1.2.0-4 (armhf, arm64, s390x, amd64, i386, ppc64el)
libalgorithm-svm-perl/0.13-2build2 (s390x)
libconvert-binary-c-perl/0.78-1build2 (amd64)
kauth/5.44.0-0ubuntu1 (i386)
libkdegames-kde4/unknown (amd64)
openssh/1:7.6p1-4ubuntu0.3 (armhf, arm64, s390x, amd64, i386, ppc64el)
keditbookmarks/17.12.3-0ubuntu1 (ppc64el)
jovie/unknown (armhf)
kdepim-runtime/4:17.12.3-0ubuntu2 (armhf)
libscalar-util-numeric-perl/0.40-1build3 (s390x)
pgpdump/unknown (armhf)
libdevice-cdio-perl/0.4.0-3 (armhf)
octave-sockets/1.2.0-3 (armhf, arm64, s390x, amd64, i386, ppc64el)
octave-gsl/2.1.0-3 (armhf, arm64, s390x, amd64, i386, ppc64el)
libdbd-odbc-perl/1.56-1build1 (armhf)
libnet-dbus-perl/1.1.0-4build2 (armhf)
linux-aws-5.3/unknown (arm64)
libalgorithm-permute-perl/0.16-1 (s390x)
xdg-desktop-portal/1.0.3-0ubuntu0.2 (i386, ppc64el)
octave-ltfat/2.2.0+dfsg-7 (s390x, amd64, i386, ppc64el)
octave-geometry/3.0.0-6 (armhf, arm64, s390x, amd64, i386, ppc64el)
octave-linear-algebra/2.2.2-4 (armhf, arm64, s390x, amd64, i386, ppc64el)
octave-nurbs/1.3.13-4 (armhf, arm64, s390x, amd64, i386, ppc64el)
devscripts/2.17.12ubuntu1.1 (armhf, arm64, s390x, amd64, i386, ppc64el)
meliae/0.4.0+bzr199-3build1 (ppc64el)
libocas/unknown (armhf)
k3d/unknown (armhf)
firefox/80.0.1+build1-0ubuntu0.18.04.1 (armhf)
libb-hooks-op-check-perl/unknown (armhf)
octave-quaternion/2.4.0-4 (armhf, arm64, s390x, amd64, i38...

Read more...

Revision history for this message
Martin Unzner (logout22) wrote :

Tested glibc/2.27-3ubuntu1.3 for a week on a regular Ubuntu workstation, no problems detected.

Patch itself is already tried and tested, will fix the issue that we encountered, but is hard to reproduce and was therefore not explicitly retested (mere user regression testing).

From my side you can go ahead and release the update.

tags: added: verification-done-bionic
removed: verification-needed-bionic
tags: added: fr-152
Revision history for this message
Łukasz Zemczak (sil2100) wrote : Update Released

The verification of the Stable Release Update for glibc has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package glibc - 2.27-3ubuntu1.3

---------------
glibc (2.27-3ubuntu1.3) bionic; urgency=medium

  [ Balint Reczey ]
  * debian/gbp.conf: Add initial configuration
  * debian/control.in/main: Add Vcs-* pointing to Ubuntu packaging repository
  * arm64: Enable searching shared libraries in atomics/ on LSE HW
  * Ship arm64 variant with LSE support in libc6-lse (LP: #1885012)
  * Run tests of libc6-lse on HW supporting LSE
  * debian/patches/git-updates.diff: update from upstream stable branch
    - pthread_cond_broadcast: Fix waiters-after-spinning case
    - Fix SSe2-based memmove corrupting memory (CVE-2017-18269)
    - Fix strstr() performance regression on Haswell processors
    - Support Japanese new era "令和 (Reiwa)"
    - io: Remove copy_file_range emulation
    (LP: #1851263, #1858203, #1838327, #1797335, #1756209, #1853193)
  * XFAIL stdlib/tst-getrandom (LP: #1891403)
  * debian/testsuite-xfail-debian.mk: XFAIL new tst-support_descriptors

  [ Thadeu Lima de Souza Cascardo ]
  * tests: Make preadwritev2 invalid flags tests unsupported (LP: #1770480)

  [ Andreas Hasenack ]
  * branch-pthread_rwlock_trywrlock-hang-23844.patch:
    nptl: Fix pthread_rwlock_try*lock stalls (Bug 23844) (LP: #1864864)

 -- Balint Reczey <email address hidden> Wed, 02 Sep 2020 11:18:37 +0200

Changed in glibc (Ubuntu Bionic):
status: Fix Committed → Fix Released
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