Bug 1325622

Summary:	PackageKit-command-not-found bash fork-bomb ; system crash
Product:	[Fedora] Fedora	Reporter:	Kevin O'Connor <kevin>
Component:	PackageKit	Assignee:	Richard Hughes <rhughes>
Status:	CLOSED EOL	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	23	CC:	jonathan, klember, nicolas, rdieter, rhughes, smparrish
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-12-20 19:53:44 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description Kevin O'Connor 2016-04-10 02:05:39 UTC

Description of problem:

If a command is run that isn't in the path, then the command_not_found_handle() bash helper could attempt to run `basename`.  However, if the path is not set properly, then basename may not be found - which triggers command_not_found_handler() - which leads to an infinite loop.  Each loop  launches a new instance of bash.  Eventually the machine launches thousands of bash instances which causes the system to become unresponsive and then unstable.

Common autoconf setup tools (eg, ./configure) purposely set an invalid path to attempt to determine the path separator character which triggers this error.


Version-Release number of selected component (if applicable):

PackageKit-command-not-found-1.0.11-1.fc23.x86_64


How reproducible:

100%


Steps to Reproduce:
1. wget 'https://ftp.gnu.org/pub/gnu/ncurses/ncurses-5.9.tar.gz'
2. tar xfz ncurses-5.9.tar.gz ; cd ncurses-5.9
3. bash ./configure

Actual results:

System unresponsive leading to eventual system instability


Expected results:

configure script successfully runs


Additional info:

To trigger this issue, the configure script does need to be run with "bash ./configure" -- the issue does not occur if "./configure" is used.  The openwrt build system uses the former, however, which is how I found this.

Other packages (besides ncurses) that use the autoconf stuff also exhibit the same problem.

Comment 1 Kevin O'Connor 2016-04-25 13:33:50 UTC

Hi, can I get an update on this error?

Comment 2 nmorey 2016-06-15 06:52:47 UTC

I hit the same bug yesterday. managed to save my session by launching a kill of all bash in a loop.

The cleanest way to solve this would be to unregister the command_not_found_handler in the the handle and reenable it at the end.

Comment 3 Fedora End Of Life 2016-11-25 07:18:59 UTC

This message is a reminder that Fedora 23 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 23. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as EOL if it remains open with a Fedora  'version'
of '23'.

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Although we aim to fix as many bugs as possible during every release's 
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Comment 4 Fedora End Of Life 2016-12-20 19:53:44 UTC

Fedora 23 changed to end-of-life (EOL) status on 2016-12-20. Fedora 23 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

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