resolved incorrectly limits TCP reply to edns0 payload

[Dan Streetman]

[impact]

glibc's getaddrinfo() uses EDNS0 to talk to resolved, and it sets its payload limit to 1200. When the response is larger than 1200, resolved will limit the response and set the truncate flag. This causes getaddrinfo() to switch to TCP and request again, but glibc incorrectly keeps the EDNS0 RR opt, with the same 1200 payload limit. Most dns nameservers ignore EDNS0 payload limit for TCP, since per RFC it applies only to UDP, but resolved does not and again marks the response as truncated. This prevents getaddrinfo() from being able to resolve any records with a response over 1200 bytes.

[test case]

use ping or telnet, which use getaddrinfo(), to lookup an A record with a lot of results, like toomany100.ddstreet.org

$ telnet toomany100.ddstreet.org
telnet: could not resolve toomany100.ddstreet.org/telnet: Temporary failure in name resolution

[regression potential]

any regression would likely result in failure to correctly lookup a hostname or to provide the correct response to a local client.

[other info]

note that on Bionic, this also requires backporting TCP pipelining support in the stub resolver.

[Steve Langasek (vorlon)]

Hello Dan, or anyone else affected,

Accepted systemd into disco-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/systemd/240-6ubuntu5.8 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 and change the tag from verification-needed-disco to verification-done-disco. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-disco. 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.

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted systemd (240-6ubuntu5.8) for disco have finished running.
The following regressions have been reported in tests triggered by the package:

prometheus-bind-exporter/unknown (armhf)
php7.2/7.2.24-0ubuntu0.19.04.1 (armhf)
gvfs/1.40.1-1ubuntu0.1 (ppc64el)
pdns-recursor/unknown (armhf)
webhook/unknown (armhf)
munin/2.0.47-1ubuntu3 (armhf, arm64)
systemd/240-6ubuntu5.8 (ppc64el)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/disco/update_excuses.html#systemd

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

[Łukasz Zemczak (sil2100)]

Hello Dan, or anyone else affected,

Accepted systemd into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/systemd/237-3ubuntu10.32 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 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.

[Dan Streetman (ddstreet)]

ubuntu@lp1849733-d:~$ dpkg -l systemd|grep ii
ii systemd 240-6ubuntu5.7 amd64 system and service manager
ubuntu@lp1849733-d:~$ telnet toomany100.ddstreet.org
telnet: could not resolve toomany100.ddstreet.org/telnet: Temporary failure in name resolution

ubuntu@lp1849733-d:/etc/systemd/network$ dpkg -l systemd|grep ii
ii systemd 240-6ubuntu5.8 amd64 system and service manager
ubuntu@lp1849733-d:/etc/systemd/network$ telnet toomany100.ddstreet.org
Trying 10.254.201.100...

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted systemd (237-3ubuntu10.32) for bionic have finished running.
The following regressions have been reported in tests triggered by the package:

gvfs/1.36.1-0ubuntu1.3.3 (ppc64el)
linux/unknown (ppc64el)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/bionic/update_excuses.html#systemd

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

[Dan Streetman (ddstreet)]

ubuntu@lp1849733-b:~$ dpkg -l systemd|grep ii
ii systemd 237-3ubuntu10.31 amd64 system and service manager
ubuntu@lp1849733-b:~$ telnet toomany100.ddstreet.org
telnet: could not resolve toomany100.ddstreet.org/telnet: Temporary failure in name resolution

ubuntu@lp1849733-b:~$ dpkg -l systemd|grep ii
ii systemd 237-3ubuntu10.32 amd64 system and service manager
ubuntu@lp1849733-b:~$ telnet toomany100.ddstreet.org
Trying 10.254.201.100...

[Steve Langasek (vorlon)]

Hello Dan, or anyone else affected,

Accepted systemd into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/systemd/237-3ubuntu10.33 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 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.

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted systemd (237-3ubuntu10.33) for bionic have finished running.
The following regressions have been reported in tests triggered by the package:

gvfs/1.36.1-0ubuntu1.3.3 (ppc64el, amd64)
dovecot/1:2.2.33.2-1ubuntu4.5 (armhf)
umockdev/0.11.1-1 (ppc64el)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/bionic/update_excuses.html#systemd

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

[Dan Streetman (ddstreet)]

ubuntu@lp1849733-b:~$ dpkg -l systemd|grep ii
ii systemd 237-3ubuntu10.31 amd64 system and service manager
ubuntu@lp1849733-b:~$ telnet toomany100.ddstreet.org
telnet: could not resolve toomany100.ddstreet.org/telnet: Temporary failure in name resolution

ubuntu@lp1849733-b:~$ dpkg -l systemd|grep ii
ii systemd 237-3ubuntu10.33 amd64 system and service manager
ubuntu@lp1849733-b:~$ telnet toomany100.ddstreet.org
Trying 10.254.201.100...

[Launchpad Janitor (janitor)]

This bug was fixed in the package systemd - 240-6ubuntu5.8

---------------
systemd (240-6ubuntu5.8) disco; urgency=medium

  [ Victor Tapia ]
  * d/p/resolved_disable-connection-downgrade-when-DNSSEC-yes.patch
    Fix regression introduced by
    resolved-Mitigate-DVE-2018-0001-by-retrying-NXDOMAIN-with.patch when
    DNSSEC=yes (LP: #1796501)

  [ Dan Streetman ]
  * d/p/lp1840640-shared-seccomp-add-sync_file_range2.patch:
    allow sync_file_range2 in nspawn container (LP: #1840640)
  * d/p/lp1847527-journal-remote-do-not-request-Content-Length-if-Tran.patch:
    do not request Content-Length if Transfer-Encoding is chunked
    (LP: #1847527)
  * d/t/storage: fix flaky test
    (LP: #1847815)
  * d/p/lp1843381-dell_passthrough_skip_rename_retry.patch,
    debian/extra/rules/73-usb-net-by-mac.rules:
    fix rename delay for systems using "Dell MAC passthrough"
    (LP: #1843381)
  * d/p/lp1849733/0001-resolved-if-we-can-t-append-EDNS-OPT-RR-then-indicat.patch,
    d/p/lp1849733/0002-resolved-don-t-let-EDNS0-OPT-dgram-size-affect-TCP.patch:
    ignore EDNS0 payload limit when responding over TCP (LP: #1849733)
  * d/p/lp1849658-resolved-set-stream-type-during-DnsStream-creation.patch:
    - Fix bug in refcounting TCP stream types (LP: #1849658)
  * d/extra/dhclient-enter-resolved-hook:
    - only restart resolved if dhclient conf changed (LP: #1805183)

  [ Balint Reczey ]
  * d/p/test-execute-Filter-dev-.lxc-in-exec-dynamicuser-statedir.patch:
    fix test breakage due to running in nested lxd container
    (LP: #1845337)

 -- Dan Streetman <email address hidden> Fri, 04 Oct 2019 09:06:58 -0400

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for systemd 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.

[Launchpad Janitor (janitor)]

This bug was fixed in the package systemd - 237-3ubuntu10.33

---------------
systemd (237-3ubuntu10.33) bionic; urgency=medium

  * d/p/lp1852754/0001-network-do-not-re-set-MTU-when-current-and-requested.patch,
    d/p/lp1852754/0002-network-call-link_acquire_conf-and-link_enter_join_n.patch,
    d/p/lp1852754/0003-network-prohibit-to-set-MTUBytes-and-UseMTU-simultan.patch:
    - Complete link setup after setting mtu (LP: #1852754)

systemd (237-3ubuntu10.32) bionic; urgency=medium

  [ Victor Tapia ]
  * d/p/resolved_disable-connection-downgrade-when-DNSSEC-yes.patch
    Fix regression introduced by
    resolved-Mitigate-DVE-2018-0001-by-retrying-NXDOMAIN-with.patch when
    DNSSEC=yes (LP: #1796501)

  [ Dan Streetman ]
  * d/p/fix-typo-lp1668771-resolved-switch-cache-option-to-a-tri-state-option-s.patch:
    - Fix typo in previous patch
  * d/p/lp1840640-shared-seccomp-add-sync_file_range2.patch:
    - allow sync_file_range2 in nspawn container
      (LP: #1840640)
  * d/p/lp1783994-dissect-Don-t-count-RPMB-and-boot-partitions-8609.patch:
    - avoid systemd-gpt-auto-generator failure if mmc dev present
      (LP: #1783994)
  * d/p/lp1832672-resolved-rework-parsing-of-etc-hosts.patch:
    - do not fail entire file on error when parsing /etc/hosts
    - parse # char anywhere in line as start of comment
      (LP: #1832672)
  * d/p/lp1843381-dell_passthrough_skip_rename_retry.patch,
    debian/extra/rules/73-usb-net-by-mac.rules:
    - fix rename delay for systems using "Dell MAC passthrough"
      (LP: #1843381)
  * d/p/lp1849733/0001-resolved-longlived-TCP-connections.patch,
    d/p/lp1849733/0002-resolved-line-split-dns_stream_new-function-signatur.patch,
    d/p/lp1849733/0003-resolved-add-some-assert-s.patch,
    d/p/lp1849733/0004-stream-track-type-of-DnsStream-object.patch,
    d/p/lp1849733/0005-llmnr-add-comment-why-we-install-no-complete-handler.patch,
    d/p/lp1849733/0006-resolved-restart-stream-timeout-whenever-we-managed-.patch,
    d/p/lp1849733/0007-resolved-only-call-complete-with-zero-argument-in-LL.patch,
    d/p/lp1849733/0008-resolved-add-comment-to-dns_stream_complete-about-it.patch,
    d/p/lp1849733/0009-resolved-keep-stub-stream-connections-up-for-as-long.patch,
    d/p/lp1849733/0010-resolved-if-we-can-t-append-EDNS-OPT-RR-then-indicat.patch,
    d/p/lp1849733/0011-resolved-don-t-let-EDNS0-OPT-dgram-size-affect-TCP.patch,
    d/p/lp1849733/0012-resolved-add-new-accessor-dns_stream_take_read_packe.patch,
    d/p/lp1849733/0013-resolve-do-not-complete-stream-transaction-when-it-i.patch:
    - add TCP pipelining to handle getaddrinfo() fallback to TCP
    - ignore EDNS0 payload limit when responding over TCP (LP: #1849733)
  * d/p/lp1849658-resolved-set-stream-type-during-DnsStream-creation.patch:
    - Fix bug in refcounting TCP stream types (LP: #1849658)
  * d/p/lp1850704/0001-networkd-Unify-set-MTU.patch,
    d/p/lp1850704/0002-network-drop-redundant-lines.patch:
    - Fix setting mtu if interface already up (LP: #1850704)
  * d/extra/dhclient-enter-resolved-hook:
    - only restart resolved if dhclient conf changed (LP: #1805183)

 -- Dan Streetman <email address hidden> Fri, 15 Nov 2019 10:01:16 -0500