aptitude segfaults during dependency resolution

[Rogério Theodoro de Brito]

[Impact]

Aptitude regularly crashes when trying to mark packages for deletion due to an infinite loop in a recursive function (improperly handled circular dependencies).

[Test Case]

On a fresh English install of Ubuntu 15.10 desktop:

1. Start up aptitude: sudo aptitude
2. Mark the following packages as automatically installed (select them and
   press Shift-M):
     * language-pack-en
     * language-pack-en-base
     * language-pack-gnome-en
     * language-pack-gnome-en-base
   Aptitude should now show all four packages as marked for deletion.
3. Mark language-pack-gnome-en-base for purge by selecting it and pressing
   '_' (underscore).

If the bug is not fixed, aptitude will crash. (Your terminal will likely be in a bad state. Run 'reset' to fix it.)

[Regression Potential]

The patch alters the logic used to automatically mark packages for deletion. Any regressions should appear there.

The patch is cherry-picked from the upstream Git repository, so upstream recognizes the bug and approves of this fix. However, upstream might have committed additional related changes (e.g., to fix a hypothetical flaw in this patch) without us realizing it.

[Original Description]

Hi.

I just installed a new Ubuntu MATE 15.10 for my mom and I was selecting packages when aptitude simply crashed. I am using (for reasons beyond my control right now) the 32 bit version if that matters.

I don't know if I can reproduce the problem or not, but I may try (despite the fact I do not have frequent access to this computer).

If any further information is needed, please let me know.

Thanks,

Rogério Brito.

ProblemType: Crash
DistroRelease: Ubuntu 15.10
Package: aptitude 0.7.3-1ubuntu1
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-11-generic i686
NonfreeKernelModules: wl
ApportVersion: 2.19.1-0ubuntu2
Architecture: i386
Date: Sat Oct 17 21:17:03 2015
ExecutablePath: /usr/bin/aptitude-curses
InstallationDate: Installed on 2015-10-17 (0 days ago)
InstallationMedia: Ubuntu-MATE 15.10 "Wily Werewolf" - Alpha i386 (20150924)
ProcCmdline: aptitude
SegvAnalysis: Skipped: missing required field "Disassembly"
Signal: 11
SourcePackage: aptitude
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

== Regression details ==
Discovered in version: 0.7.3-1ubuntu1
Last known good version: 0.6.11-1ubuntu3

[Apport retracing service (apport)]

StacktraceTop:
 stringcasecmp (BEnd=<optimized out>, B=0x8037cb6e "aptitude::Purge-Unused", A=...) at ../build/include/apt-pkg/strutl.h:143
 Configuration::Lookup (this=0x80dc72f8, Head=0x80dc7308, S=0x8037cb6e "aptitude::Purge-Unused", Len=@0xbf396058: 8, Create=@0xbf39609b: false) at /build/apt-J_Z9yD/apt-1.0.10.2ubuntu1/apt-pkg/contrib/configuration.cc:102
 Configuration::Lookup (this=0x80dc72f8, Name=0x8037cb6e "aptitude::Purge-Unused", Create=@0xbf39609b: false) at /build/apt-J_Z9yD/apt-1.0.10.2ubuntu1/apt-pkg/contrib/configuration.cc:138
 Lookup (Name=0x8037cb6e "aptitude::Purge-Unused", this=0x80dc72f8) at ../build/include/apt-pkg/configuration.h:68
 Configuration::FindB (this=0x80dc72f8, Name=0x8037cb6e "aptitude::Purge-Unused", Default=@0xbf3960cc: false) at /build/apt-J_Z9yD/apt-1.0.10.2ubuntu1/apt-pkg/contrib/configuration.cc:303

[Rogério Theodoro de Brito (rbrito)]

I think that I found a way to (at least partially) reproduce the problem: if I press _ (underscore) after I have selected packages to be (automatically) uninstalled (so that they are purged instead of just uninstalled), then I get the segfault that described before.

Again, if any further information is needed, please let me know.

Rogério.

[Launchpad Janitor (janitor)]

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

[Richard Hansen (rhansen)]

This bug has been fixed in the upstream Debian version. A patch is available here:
https://bugs.debian.org/cgi-bin/bugreport.cgi?att=1;bug=801430;filename=0001-Fix-for-circular-dependencies-in-internal_mark_delet.patch;msg=54

Upstream commit:
https://anonscm.debian.org/cgit/aptitude/aptitude.git/commit/?id=d6b67aba318ab83752f10adabf1b0490d2c88b39

[Richard Hansen (rhansen)]

Attached is a debdiff containing a fix for this problem. I have also uploaded a fixed package to my PPA:

https://launchpad.net/~rhansen/+archive/ubuntu/bug1507211

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "debdiff.patch" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

[Brian Murray (brian-murray)]

This is fixed in Xenial, the development release of Ubuntu which will become 16.04, if you'd like to see this fixed in Wily please add a test case following the procedure documented at wiki.ubuntu.com/StableReleaseUpdates. Thanks!

[Brian Murray (brian-murray)]

I'll go ahead and sponsor this, thanks for working on it!

[Rogério Theodoro de Brito (rbrito)]

Hi.

On Dec 15 2015, Brian Murray wrote:
> I'll go ahead and sponsor this, thanks for working on it!

Thanks for both of you for working on this.

--
Rogério Brito : rbrito@{ime.usp.br,gmail.com} : GPG key 4096R/BCFCAAAA
http://cynic.cc/blog/ : github.com/rbrito : profiles.google.com/rbrito
DebianQA: http://qa.debian.org/developer.php?login=rbrito%40ime.usp.br

[Chris J Arges (arges)]

Hello Rogério, or anyone else affected,

Accepted aptitude into wily-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/aptitude/0.7.3-1ubuntu1.1 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 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 to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

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

[Richard Hansen (rhansen)]

0.7.3-1ubuntu1.1 works for me. Thanks!

[Launchpad Janitor (janitor)]

This bug was fixed in the package aptitude - 0.7.3-1ubuntu1.1

---------------
aptitude (0.7.3-1ubuntu1.1) wily; urgency=medium

  * Cherry-pick upstream commit d6b67ab from 0.7.4 to fix an infinite
    loop and crash when determining which packages can be
    automatically deleted (#801430). (Closes: LP: #1507211)

 -- Richard Hansen <email address hidden> Tue, 15 Dec 2015 11:19:01 -0800

[Chris J Arges (arges)]

The verification of the Stable Release Update for aptitude has completed successfully and the package has now been 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.