Ubuntu
apt-cacher-ng package

apt-cacher-ng data corruption with HTTP headers

Bug #1162876 reported by Chris J Arges on 2013-04-01

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	apt-cacher-ng (Ubuntu)	Fix Released	Undecided	Unassigned
	Precise	Fix Released	Medium	Chris J Arges

Bug Description

apt-cacher-ng is reporting hash mismatches for packages in an archive at random. This is due to the fact that apt-cacher-ng is storing the HTTP headers related to the package download in the .deb file.

This issue happens intermittently on precise apt-cacher-ng 0.7.2-1ubuntu1, but seems to be fixed in 0.7.4.

SRU Justification:
[Impact]

* When using apt-cacher-ng hash mismatches failures for packages can cause problems when installing packages.

[Test Case]

* Set up apt-cacher-ng
* Intermittent failures due to hash-mismatches may occur in versions <= 0.7.2-1ubuntu1

[Regression Potential]

* This adds a few patches that fix the issue. Unfortuantely I was unable to find an upstream VCS to be able to separate out patches from each other. Therfore I tried to remove the very obvious bits of the code that did not address the issue. All of this code is already in newer versions of the package.
* This package has been tested in an environment with a apt-cache-ng server and 10 client machines and has been run for days without any hash mismatches.

See original description

Tags:

Related branches

lp:ubuntu/precise-proposed/apt-cacher-ng

Revision history for this message

Chris J Arges (arges) wrote on 2013-04-01:

hash-mismatch-bug-1162876.log Edit (1.2 KiB, text/plain)

Attached is an example log of the problem.

Changed in apt-cacher-ng (Ubuntu):
status:	In Progress → Fix Released
assignee:	Chris J Arges (arges) → nobody
importance:	Medium → Undecided
Changed in apt-cacher-ng (Ubuntu Precise):
importance:	Undecided → Medium
status:	New → In Progress
assignee:	nobody → Chris J Arges (arges)

Revision history for this message

Chris J Arges (arges) wrote on 2013-04-01:

fix_lp1162876_precise.debdiff Edit (32.4 KiB, text/plain)

Attached is a patch that fixes the issue.
A test build is here:
http://people.canonical.com/~arges/lp1162876/

Chris J Arges (arges) on 2013-04-01

description:

updated

Revision history for this message

Colin Watson (cjwatson) wrote on 2013-04-08:

Sponsored, thanks!

Revision history for this message

Steve Langasek (vorlon) wrote on 2013-04-09:

Chris, I'm accepting this into precise-proposed because from Colin I understand re-validating a prospective patch is quite time-consuming with a long customer round-trip. But the patch here is suboptimal; in future SRUs, please avoid code changes unrelated to the bugs you're trying to fix.

In this case, there are:

- renamed members in a class (m_nReqRangeFrom, m_nReqRangeTo)
- an API change that affects parsing behavior when an option appears more than once in the config, which is unrelated to the bugs here (SetOption)
- renamed defines (EFLAG_DISCON, EFLAG_DO_DISCON)
- logging changes

All of these are unrelated to the bugfixes, and make code review of the diff more time-consuming and error-prone. I've satisfied myself that they're reasonably safe here, but such changes should not be included in an SRU - an SRU should include the minimal change necessary to fix the bug.

Changed in apt-cacher-ng (Ubuntu Precise):
status:	In Progress → Fix Committed
tags:	added: verification-needed

Revision history for this message

Steve Langasek (vorlon) wrote on 2013-04-09: Please test proposed package

Hello Chris, or anyone else affected,

Accepted apt-cacher-ng into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/apt-cacher-ng/0.7.2-1ubuntu2 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!

Jonathan Davies (jpds) on 2013-04-09

tags:

added: verification-done
removed: verification-needed

Revision history for this message

Chris J Arges (arges) wrote on 2013-04-09:

@vorlon,
Thanks for the feedback, I agree completely with your assessment. I did attempt this; however, I was a bit too conservative with hacking down the patch. Noted for next time.

Revision history for this message

Colin Watson (cjwatson) wrote on 2013-04-16: Update Released

The verification of this Stable Release Update 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 regresssions.

Revision history for this message

Launchpad Janitor (janitor) wrote on 2013-04-16:

This bug was fixed in the package apt-cacher-ng - 0.7.2-1ubuntu2

---------------
apt-cacher-ng (0.7.2-1ubuntu2) precise; urgency=low

   [ Eduard Bloch ]
   * Option to disable Range/If-Range for volatile files (LP: #983128)
   * Fixes storage of HTTP header data in cached files under certain
         circumstances (now really closes: #644959) (LP: #1162876)
-- Chris J Arges <email address hidden> Tue, 09 Apr 2013 00:21:04 +0100