Bug 1640875 - ofproto-dpif-xlate: Avoid deadlock on multicast snooping recursion.
Summary: ofproto-dpif-xlate: Avoid deadlock on multicast snooping recursion.
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat OpenStack
Classification: Red Hat
Component: openvswitch
Version: 13.0 (Queens)
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
: ---
Assignee: Assaf Muller
QA Contact: Eran Kuris
URL:
Whiteboard:
Depends On: 1643071
Blocks:
TreeView+ depends on / blocked
 
Reported: 2018-10-19 03:36 UTC by Brendan Shephard
Modified: 2022-03-13 16:05 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
: 1640930 1643065 (view as bug list)
Environment:
Last Closed: 2020-02-25 14:25:17 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Github openvswitch ovs-issues issues 153 0 None closed ovs-vswitchd deadlock with ICMPv6 multicast listener report packet 2020-08-28 19:12:56 UTC
Red Hat Issue Tracker OSP-13701 0 None None None 2022-03-13 16:05:00 UTC

Description Brendan Shephard 2018-10-19 03:36:19 UTC
Description of problem:
Issue: https://github.com/openvswitch/ovs-issues/issues/153
Copied from the github issue: https://github.com/openvswitch/ovs/commit/ed56f8bd6a668df3664f68b00c5396c268aa1821

Until now, OVS did multicast snooping outputs holding the read-lock on
the mcast_snooping object.  This could recurse via a patch port to try to
take the write-lock on the same object, which deadlocked.  This patch fixes
the problem, by releasing the read-lock before doing any outputs.

It would probably be better to use RCU for mcast_snooping.  That would be
a bigger patch and less suitable for backporting.

Version-Release number of selected component (if applicable):
2.9

How reproducible:


Steps to Reproduce:
1.
2.
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Actual results:


Expected results:


Additional info:
Creating this BZ to address customer concern about upstream issue that has recently been patched. Looking to backport the fix into RHEL OvS release for OpenStack.

Comment 3 Flavio Leitner 2018-10-25 13:05:42 UTC
Looks like the patch is backported in upstream already, so I opened the RHEL bugs to track the backport. I am proposing for the next batch FDP:18.12.

2.10 https://bugzilla.redhat.com/show_bug.cgi?id=1643065
2.9 https://bugzilla.redhat.com/show_bug.cgi?id=1643071


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