Bug 1921283 - fix MCS blocking iptables rules
Summary: fix MCS blocking iptables rules
Alias: None
Product: OpenShift Container Platform
Classification: Red Hat
Component: Networking
Version: 4.7
Hardware: Unspecified
OS: Unspecified
Target Milestone: ---
: 4.5.z
Assignee: Dan Winship
QA Contact: Kedar Kulkarni
Depends On: 1921274
TreeView+ depends on / blocked
Reported: 2021-01-27 20:28 UTC by Dan Winship
Modified: 2021-03-03 04:40 UTC (History)
8 users (show)

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.
Clone Of: 1921274
Last Closed: 2021-03-03 04:40:35 UTC
Target Upstream Version:

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Github openshift ovn-kubernetes pull 426 0 None open Bug 1921283: [4.5] Fix MCS-blocking iptables rules 2021-02-10 15:36:49 UTC
Red Hat Product Errata RHSA-2021:0428 0 None None None 2021-03-03 04:40:55 UTC

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

I was able to verify the BZ on OVN cluster using `curl` command to curl 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
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


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.


Note You need to log in before you can comment on or make changes to this bug.