Bug 1418824

Summary:	Memory leak allows shaping the heap in pkexec.c
Product:	Red Hat Enterprise Linux 6	Reporter:	Leonard den Ottolander <leonard-rh-bugzilla>
Component:	polkit	Assignee:	Miloslav Trmač <mitr>
Status:	CLOSED WONTFIX	QA Contact:	BaseOS QE Security Team <qe-baseos-security>
Severity:	low	Docs Contact:
Priority:	low
Version:	6.8	CC:	pkis
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
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Clones:	1418825 (view as bug list)		Environment:
Last Closed:	2017-12-06 10:38:46 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1418825

Description Leonard den Ottolander 2017-02-02 19:57:47 UTC

In polkit-0.96-11.el6 pkexec.c is a memory leak that can be used to "spray the heap". Compare https://googleprojectzero.blogspot.nl/2014/08/the-poisoned-nul-byte-2014-edition.html "Step 5: Aha! use a command-line argument spray to effect a heap spray and collide the heap into the stack". The article describes an effective attack using this ability to "heap spray".

This issue has been fixed upstream by disallowing multiple user invocations:

https://cgit.freedesktop.org/polkit/commit/src/programs/pkexec.c?id=6c992bc8aefa195a41eaa41c07f46f17de18e25c

Similar issues exist in pkcheck.c but since that binary is not setuid the memory leaks in that binary are not quite as acute. Compare bug #1418278 & #1418287 .

Comment 2 Jan Kurik 2017-12-06 10:38:46 UTC

Red Hat Enterprise Linux 6 is in the Production 3 Phase. During the Production 3 Phase, Critical impact Security Advisories (RHSAs) and selected Urgent Priority Bug Fix Advisories (RHBAs) may be released as they become available.

The official life cycle policy can be reviewed here:

http://redhat.com/rhel/lifecycle

This issue does not meet the inclusion criteria for the Production 3 Phase and will be marked as CLOSED/WONTFIX. If this remains a critical requirement, please contact Red Hat Customer Support to request a re-evaluation of the issue, citing a clear business justification. Note that a strong business justification will be required for re-evaluation. Red Hat Customer Support can be contacted via the Red Hat Customer Portal at the following URL:

https://access.redhat.com/