Bug 1989686

Summary:	httpd 100% CPU after using Thunderbird CalDAV client with HTTP/2
Product:	[Fedora] Fedora	Reporter:	Pim Zandbergen <p.zandbergen>
Component:	cyrus-imapd	Assignee:	Pavel Zhukov <pavel>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	34	CC:	j, pavel, vanmeeuwen+fedora, zdohnal
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:	cyrus-imapd-3.2.4-7.fc34	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-08-13 01:20:55 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Pim Zandbergen 2021-08-03 17:50:59 UTC

Description of problem:

After a Thunderbird CalDAV client connects to httpd using HTTP/2 (which it attempts by default), the httpd process gets stuck consuming all available CPU capacity.


Version-Release number of selected component (if applicable):
Cyrus-imapd-3.2.4-5.fc34.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Configure cyrus-imapd as a CalDAV server
2. Configure Thunderbird as a CalDAV client
3. Create a successful connection


Actual results:
Client does not notice anything wrong
Server CPU will hit 100%


Expected results:
Server CPU usage is normal


Additional info:
Can be worked around by disabling HTTP/2 on all clients
Reported on Debian and upstream
Fixed upstream in version 3.2.5

Comment 1 Pim Zandbergen 2021-08-03 17:54:22 UTC

The correct upstream URL is https://github.com/cyrusimap/cyrus-imapd/issues/3180

Comment 2 Fedora Update System 2021-08-04 11:40:15 UTC

FEDORA-2021-d39a5cc1a2 has been submitted as an update to Fedora 34. https://bodhi.fedoraproject.org/updates/FEDORA-2021-d39a5cc1a2

Comment 3 Fedora Update System 2021-08-05 01:16:45 UTC

FEDORA-2021-d39a5cc1a2 has been pushed to the Fedora 34 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2021-d39a5cc1a2`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2021-d39a5cc1a2

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 4 Fedora Update System 2021-08-13 01:20:55 UTC

FEDORA-2021-d39a5cc1a2 has been pushed to the Fedora 34 stable repository.
If problem still persists, please make note of it in this bug report.