Bug 1921283

Summary:	fix MCS blocking iptables rules
Product:	OpenShift Container Platform	Reporter:	Dan Winship <danw>
Component:	Networking	Assignee:	Dan Winship <danw>
Networking sub component:	ovn-kubernetes	QA Contact:	Kedar Kulkarni <kkulkarn>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	high
Priority:	urgent	CC:	anbhat, bbennett, ealcaniz, kholtz, kkulkarn, mmethot, openshift-bugzilla-robot, rkhan
Version:	4.7
Target Milestone:	---
Target Release:	4.5.z
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	Cause: An incorrect ovn-kubernetes security rule that was supposed to only block outbound connections also blocked some inbound connections. Consequence: In the general case, around 1 in 10,000 attempts to connect to a pod would fail spuriously. However, if a client intentionally used a restricted range of source ports, it could hit the buggy rule more frequently. Fix: The iptables rule was fixed to only block the intended connections. Result: No spurious failures.	Story Points:	---
Clone Of:	1921274	Environment:
Last Closed:	2021-03-03 04:40:35 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:	1921274
Bug Blocks:

Comment 2 Kedar Kulkarni 2021-02-11 16:09:36 UTC


Hi,
I was able to verify the BZ on OVN cluster using `curl` command to curl 172.30.0.1 as per the instructions. Here's the snippet of one of the curl calls:

===========================================================================================
oc run -it --rm curlpod --image=curlimages/curl -- /bin/sh
If you don't see a command prompt, try pressing enter.

/ $ curl --local-port 22624 https://172.30.0.1/
curl: (60) SSL certificate problem: self signed certificate in certificate chain
More details here: https://curl.se/docs/sslcerts.html

curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.
===========================================================================================

Nightly Build used: 4.5.0-0.nightly-2021-02-11-024848


Thanks,
KK.

Comment 5 errata-xmlrpc 2021-03-03 04:40:35 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Important: OpenShift Container Platform 4.5.33 bug fix and security update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2021:0428