Ubuntu
cpustat package

cache'd pid recycling adds cached info to hash again causing double free on exit cleanup

Bug #1631050 reported by Colin Ian King
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
cpustat (Ubuntu)
Fix Released
High
Colin Ian King
Xenial
Fix Released
High
Colin Ian King

Bug Description

[XENIAL SRU]

[Impact]
Cached pid info is added to the hash table even when it's a re-used pid info causing a double free on exit cleanup. Only add pid info to hash table if it is newly allocated.

[Test Case]
Run cpustat for a long duration as follows:

cpustat 1 -T -g

..and work through a lot of processes IDs until we re-use a PID, e.g.:

stress-ng --fork 0 &

and stop cpustat with SIGINT, one hits a double free as it exits

[Regression Potential]

Minimal, the fix stops an item being added to a cache'd hash list more than once, and that is a minimal impact on the main cpustat functionality.

[Fix]
Upstream commit http://kernel.ubuntu.com/git/cking/cpustat.git/commit/?id=dc7d2fe45560c414645bc286a7cd63f13b69dc6c

See original description
Revision history for this message
Colin Ian King (colin-king) wrote :

fix commited:

commit dc7d2fe45560c414645bc286a7cd63f13b69dc6c
Author: Colin Ian King <email address hidden>
Date: Thu Oct 6 17:12:00 2016 +0100

    cpustat: only add pid info to hash table if it is new (LP: #1631050)

Changed in cpustat (Ubuntu):
status: New → In Progress
importance: Undecided → High
assignee: nobody → Colin Ian King (colin-king)
status: In Progress → Fix Committed
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package cpustat - 0.01.27-1ubuntu0

---------------
cpustat (0.01.27-1ubuntu0) yakkety; urgency=medium

  * Only add pid info to hash table if it is new (LP: #1631050)
    - fixes double free error on exit

 -- Colin King <email address hidden> Thu, 6 Oct 2016 17:17:18 +0100

Changed in cpustat (Ubuntu):
status: Fix Committed → Fix Released
Colin Ian King (colin-king)
description: updated
Changed in cpustat (Ubuntu Xenial):
status: New → In Progress
importance: Undecided → High
assignee: nobody → Colin Ian King (colin-king)
Revision history for this message
Andy Whitcroft (apw) wrote : Please test proposed package

Hello Colin, or anyone else affected,

Accepted cpustat into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/cpustat/0.01.25-1ubuntu0 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!

Changed in cpustat (Ubuntu Xenial):
status: In Progress → Fix Committed
tags: added: verification-needed
Revision history for this message
Colin Ian King (colin-king) wrote :

Given this a good thrash test on the raspi2 board where I first detected this and it no longer breaks with the latest version in -proposed. It's fixed.

tags: added: verification-done
removed: verification-needed
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package cpustat - 0.01.25-1ubuntu0

---------------
cpustat (0.01.25-1ubuntu0) xenial; urgency=medium

  * Only add pid info to hash table if it is new (LP: #1631050)
    - fixes double free error on exit

 -- Colin King <email address hidden> Thu, 6 Oct 2016 17:17:18 +0100

Changed in cpustat (Ubuntu Xenial):
status: Fix Committed → Fix Released
Revision history for this message
Martin Pitt (pitti) wrote : Update Released

The verification of the Stable Release Update for cpustat 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.

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