[Bug 1220013] Re: update-apt-xapian-index crashed with SIGSEGV in File()

[Iain Lane]

I'm not sure if this is a bug in apt, python-apt or software-center.
Here's my brain dump

ddebs.ubuntu.com currently has a package with no Description field

Package: php5-gearman-dbgsym
Priority: extra
Section: php
Installed-Size: 243
Maintainer: Debian PHP PECL Maintainers <pkg-php-pecl at lists.alioth.debian.org>
Architecture: amd64
Source: php-gearman
Version: 1.1.2-1build1
Depends: php5-gearman (= 1.1.2-1build1)
Filename: pool/universe/p/php-gearman/php5-gearman-dbgsym_1.1.2-1build1_amd64.ddeb
Size: 50610
MD5sum: 0c9b4932b6a1de927c2f4fb7e388e5d5
SHA1: 60697f6457e71e5197f2a5109d62b7e100616684
SHA256: 8f7f500dd44fa58bb0af6ac573bb22b09b55d536baf28bb20a8aabd373cbdd65
SHA512: 3809e68065c7b8e28c35143411aec449585d443a8a3101839e27671ad1129a33fe69679c9278d6ecea927e6b2b03db216a3812467306fac08826173c81ec3d32
Homepage: http://pecl.php.net/package/gearman

I used python-faulthandler to print out a python stack trace when the
segfault happens:

Current thread 0x00007fdc45a3c740:
  File "/usr/lib/python2.7/dist-packages/apt/package.py", line 273 in _translated_records
  File "/usr/lib/python2.7/dist-packages/apt/package.py", line 331 in description
  File "<stdin>", line 1 in <module>
  File "/usr/lib/python2.7/pdb.py", line 234 in default
  File "/usr/lib/python2.7/cmd.py", line 220 in onecmd
  File "/usr/lib/python2.7/pdb.py", line 279 in onecmd
  File "/usr/lib/python2.7/cmd.py", line 142 in cmdloop
  File "/usr/lib/python2.7/pdb.py", line 210 in interaction
  File "/usr/lib/python2.7/pdb.py", line 158 in user_line
  File "/usr/lib/python2.7/bdb.py", line 67 in dispatch_line
  File "/usr/lib/python2.7/bdb.py", line 49 in trace_dispatch
  File "/usr/share/apt-xapian-index/plugins/display_name.py", line 81 in index
  File "/usr/lib/python2.7/dist-packages/axi/indexer.py", line 540 in get_document_from_apt
  File "/usr/lib/python2.7/dist-packages/axi/indexer.py", line 577 in gen_documents_apt
  File "/usr/lib/python2.7/dist-packages/axi/indexer.py", line 719 in buildIndex
  File "/usr/lib/python2.7/dist-packages/axi/indexer.py", line 744 in rebuild
  File "/usr/sbin/update-apt-xapian-index", line 111 in <module>
Segmentation fault (core dumped)

display_name.py is a plugin from software-center which is doing this:

  def index(self, document, pkg):
        …
        ver = pkg.candidate

        if ver is None:
            return
        if self.val_display_name != -1:
            name = ver.summary

The `ver.summary' line is the one that triggers the segfault by
eventually calling into the crashing code in python-apt.

python/cache.cc crashes in this line in DescriptionGetFileList() at the
call to File():

        DescFile =
CppPyObject_NEW<pkgCache::PkgFileIterator>(Owner,&PyPackageFile_Type,I.File());

So I'm not sure if the problem is in python-apt here or if there's a bad
iterator coming from libapt.

** Also affects: apt (Ubuntu)
   Importance: Undecided
       Status: New

** Also affects: python-apt (Ubuntu)
   Importance: Undecided
       Status: New

** Summary changed:

- update-apt-xapian-index crashed with SIGSEGV in File()
+ python-apt can SIGSEGV when encountering Packages stanzas with no Description field (was: update-apt-xapian-index crashed with SIGSEGV in File())

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to apt-xapian-index in Ubuntu.
https://bugs.launchpad.net/bugs/1220013

Title:
  python-apt can SIGSEGV when encountering Packages stanzas with no
  Description field (was: update-apt-xapian-index crashed with SIGSEGV
  in File())

Status in “apt” package in Ubuntu:
  New
Status in “apt-xapian-index” package in Ubuntu:
  Confirmed
Status in “python-apt” package in Ubuntu:
  New

Bug description:
  Errors Bucket:
  http://errors.ubuntu.com/bug/1220013

  There are 600+ reports of this on errors.ubuntu.com.

  Something wrong

  ProblemType: CrashDistroRelease: Ubuntu 13.10
  Package: apt-xapian-index 0.45ubuntu2
  ProcVersionSignature: Ubuntu 3.11.0-4.9-generic 3.11.0-rc7
  Uname: Linux 3.11.0-4-generic i686
  ApportVersion: 2.12.1-0ubuntu3
  Architecture: i386
  CrashCounter: 1
  Date: Tue Sep  3 01:23:23 2013
  ExecutablePath: /usr/sbin/update-apt-xapian-index
  InterpreterPath: /usr/bin/python2.7
  MarkForUpload: True
  PackageArchitecture: all
  ProcCmdline: /usr/bin/python /usr/sbin/update-apt-xapian-index --quiet
  ProcEnviron:
   TERM=linux
   PATH=(custom, no user)
   SHELL=/bin/sh
  SegvAnalysis:
   Segfault happened at: 0xb6c9e020:	imul   $0x3c,(%eax),%ebp
   PC (0xb6c9e020) ok
   source "$0x3c" ok
   destination "(%eax)" (0xd7ac1000) not located in a known VMA region (needed writable region)!
  SegvReason: writing unknown VMA
  Signal: 11SourcePackage: apt-xapian-index
  StacktraceTop:
   ?? () from /usr/lib/python2.7/dist-packages/apt_pkg.so
   ?? ()
   PyObject_GetAttr ()
   PyEval_EvalFrameEx ()
   ?? ()
  Title: update-apt-xapian-index crashed with SIGSEGV in PyObject_GetAttr()
  UpgradeStatus: Upgraded to saucy on 2013-08-16 (17 days ago)
  UserGroups:

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