Bug 1418825

Summary:	Memory leak allows shaping the heap in pkexec.c
Product:	Red Hat Enterprise Linux 7	Reporter:	Leonard den Ottolander <leonard-rh-bugzilla>
Component:	polkit	Assignee:	Polkit Maintainers <polkit-devel>
Status:	CLOSED WONTFIX	QA Contact:	qe-baseos-daemons
Severity:	low	Docs Contact:
Priority:	low
Version:	7.3	CC:	fsumsal, mitr, qe-baseos-security
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:	1418824	Environment:
Last Closed:	2021-01-15 07:31:21 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:
Embargoed:
Bug Depends On:	1418824
Bug Blocks:

Description Leonard den Ottolander 2017-02-02 20:00:10 UTC

+++ This bug was initially created as a clone of Bug #1418824 +++

In polkit-112-9.el7 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 & bug #1418287 .

Comment 4 RHEL Program Management 2021-01-15 07:31:21 UTC

After evaluating this issue, there are no plans to address it further or fix it in an upcoming release.  Therefore, it is being closed.  If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.