Bug 1620290 (CVE-2018-14621)

Summary:	CVE-2018-14621 libtirpc: Infinite loop in EMFILE case in svc_vc.c
Product:	[Other] Security Response	Reporter:	Laura Pardo <lpardo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	abhgupta, ahardin, bleanhar, bmcclain, ccoleman, dbaker, dblechte, dedgar, dfediuck, eedri, jgoulding, jokerman, kkeithle, mchappel, mgoldboi, michal.skrivanek, sbonazzo, sherold, sisharma, ssaha, steved, sthangav, trankin, vbellur
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	libtirpc 1.0.2-rc2	Doc Type:	If docs needed, set a value
Doc Text:	An infinite loop vulnerability was found in libtirpc. With the port to using poll rather than select, exhaustion of file descriptors would cause the server to enter an infinite loop, consuming a large amount of CPU time and denying service to other clients until restarted.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-10 10:36:28 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:
Bug Blocks:	1620296

Description Laura Pardo 2018-08-22 21:46:07 UTC

A flaw was found in libtirpc before version 1.0.2-rc2. With the port to poll, and endless loop can be created when running out of file descriptors.


References:
https://bugzilla.novell.com/show_bug.cgi?id=968175

Upstream Patch:
http://git.linux-nfs.org/?p=steved/libtirpc.git;a=commit;h=fce98161d9815ea016855d9f00274276452c2c4b

Comment 1 Doran Moppert 2018-08-23 02:55:52 UTC

This was introduced with the port to using poll() instead of select() around 0.3.3.  Prior versions use a different strategy when EMFILE/ENFILE is hit:  the "most idle" connection is dropped before retrying.