[Bug 1549644] Re: libc6-udeb resolver segfaults when resolving local addresses with no domain

[Paul Nijjar]

** Also affects: debian-installer (Ubuntu)
   Importance: Undecided
       Status: New

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Title:
  libc6-udeb resolver segfaults when resolving local addresses with no
  domain

Status in anna package in Ubuntu:
  New
Status in debian-installer package in Ubuntu:
  New

Bug description:
  I do not know whether this bug belongs to debian-installer, anna or
  libc6-udeb, so I will follow Launchpad's suggestion.

  I install machines using preseeding, with a local apt-cacher-ng proxy
  called "apt-cache". In this case I am installing Ubuntu 14.04 . I
  install both on i386 and amd64 architectures, and am getting the same
  results.

  When installing I get the message that the installer failed to
  download a file from the mirror, during the bootstrap installer
  download. It always fails at the same point: when downloading
  libcryptsetup4-udeb, immediately after downloading
  libc6-udeb_2.19-0ubuntu6.7_amd64.udeb.

  Switching to one of the consoles, I find that name resolutions are
  failing for addresses on my local network when I do not specify a
  fully-qualified domain name, but succeeding for addresses where the
  domain is specified. Here is an example:

  ~ # ping apt-cache
  Segmentation fault
  ~ # ping apt-cache.theworkingcentre.org
  PING apt-cache.theworkingcentre.org (10.11.12.26): 56 data bytes

  In syslog I see the following suspicious entries:

  Feb 25 05:46:45 anna[3577]: DEBUG: retrieving jfsutils-udeb 1.1.15-2.1
  Feb 25 05:46:45 anna[3577]: 2016-02-25 05:46:45 URL:http://apt-cache:3142/ca.archi
  ve.ubuntu.com/ubuntu/pool/main/j/jfsutils/jfsutils-udeb_1.1.15-2.1_amd64.udeb [162
  150/162150] -> "/var/cache/anna/jfsutils-udeb_1.1.15-2.1_amd64.udeb" [1]
  Feb 25 05:46:45 anna[3577]: DEBUG: retrieving libbsd0-udeb 0.6.0-2ubuntu1
  Feb 25 05:46:45 anna[3577]: 2016-02-25 05:46:45 URL:http://apt-cache:3142/ca.archi
  ve.ubuntu.com/ubuntu/pool/main/libb/libbsd/libbsd0-udeb_0.6.0-2ubuntu1_amd64.udeb 
  [24916/24916] -> "/var/cache/anna/libbsd0-udeb_0.6.0-2ubuntu1_amd64.udeb" [1]
  Feb 25 05:46:45 anna[3577]: DEBUG: retrieving libc6-udeb 2.19-0ubuntu6.7
  Feb 25 05:46:46 anna[3577]: 2016-02-25 05:46:46 URL:http://apt-cache:3142/ca.archi
  ve.ubuntu.com/ubuntu/pool/main/e/eglibc/libc6-udeb_2.19-0ubuntu6.7_amd64.udeb [111
  8088/1118088] -> "/var/cache/anna/libc6-udeb_2.19-0ubuntu6.7_amd64.udeb" [1]
  Feb 25 05:46:47 anna[3577]: DEBUG: retrieving libcryptsetup4-udeb 2:1.6.1-1ubuntu1
  Feb 25 05:46:47 anna[3577]: Segmentation fault
  Feb 25 05:46:47 kernel: [   45.546051] wget[4856]: segfault at 14 ip 00007fe0079d5
  d66 sp 00007fffb3a959a0 error 6 in libresolv-2.19.so[7fe0079ca000+17000]
  Feb 25 05:46:47 anna[3577]: Segmentation fault

  
  The "libresolv-2.19.so" makes me think that this problem might have something to do with the security update to glibc, but I have no proof of this. 

  I do know that the installers worked before. If I change my preseed
  entries for the local cache to fully-qualified domain names then the
  installer works. If I specify an IP address for the apt-cacher-ng
  machine then the installer works.

  This happens consistently for me, on several different pieces of
  hardware.

  I will attach my syslog and dmesg output. If there are other files I
  should include, or there is a more effective way to run apport or
  ubuntu-bug or something this early in the install process, let me
  know.

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