Bug 1418824 - Memory leak allows shaping the heap in pkexec.c
Summary: Memory leak allows shaping the heap in pkexec.c
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: polkit
Version: 6.8
Hardware: Unspecified
OS: Unspecified
Target Milestone: rc
: ---
Assignee: Miloslav Trmač
QA Contact: BaseOS QE Security Team
Depends On:
Blocks: 1418825
TreeView+ depends on / blocked
Reported: 2017-02-02 19:57 UTC by Leonard den Ottolander
Modified: 2017-12-06 10:38 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
: 1418825 (view as bug list)
Last Closed: 2017-12-06 10:38:46 UTC
Target Upstream Version:

Attachments (Terms of Use)

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:


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:


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:


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