Bug 582068 (CVE-2010-1488)

Summary:	CVE-2010-1488 kernel: oom: fix the unsafe usage of badness() in proc_oom_score()
Product:	[Other] Security Response	Reporter:	Eugene Teo (Security Response) <eteo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	arozansk, davej, kmcmartin, lwang, onestero, tcallawa, vdanen
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2013-07-23 22:16:52 UTC	Type:	---
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:	579408, 582069
Bug Blocks:

Description Eugene Teo (Security Response) 2010-04-14 02:07:28 UTC

Description of problem:
proc_oom_score(task) has a reference to task_struct, but that is all. If this task was already released before we take tasklist_lock
    
- we can't use task->group_leader, it points to nowhere
    
- it is not safe to call badness() even if this task is ->group_leader, has_intersects_mems_allowed() assumes it is safe to iterate over ->thread_group list.
    
- even worse, badness() can hit ->signal == NULL
    
Add the pid_alive() check to ensure __unhash_process() was not called.
    
Also, use "task" instead of task->group_leader. badness() should return the same result for any sub-thread. Currently this is not true, but this should be changed anyway.

Upstream commit:
http://git.kernel.org/linus/b95c35e76b29ba812e5dabdd91592e25ec640e93

Comment 1 Eugene Teo (Security Response) 2010-04-14 02:09:27 UTC

Statement:

Not vulnerable. The Linux kernel as shipped with with Red Hat Enterprise Linux 3, 4, 5 and Red Hat Enterprise MRG did not include upstream commit 28b83c51 (v2.6.32-rc1) that introduced the problem.

Comment 4 Vincent Danen 2010-04-20 22:43:14 UTC

This has been assigned CVE-2010-1488