Bug 1948988

Summary:	Refcounting issue causes crashes and slow workarounds
Product:	Red Hat Enterprise Linux 8	Reporter:	Martin Kletzander <mkletzan>
Component:	glib2	Assignee:	Michael Catanzaro <mcatanza>
Status:	CLOSED ERRATA	QA Contact:	Tomas Pelka <tpelka>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	8.3	CC:	hhan, jsuchane, mboisver, tpelka, tpopela
Target Milestone:	beta	Keywords:	OtherQA, Triaged, ZStream
Target Release:	---	Flags:	pm-rhel: mirror+
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	glib2-2.56.4-12.el8	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	1953553 (view as bug list)		Environment:
Last Closed:	2021-11-09 19:35:29 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:
Bug Depends On:
Bug Blocks:	1953553

Description Martin Kletzander 2021-04-13 08:19:29 UTC

Description of problem:
Originally filed upstream as https://gitlab.gnome.org/GNOME/glib/-/issues/2031 because this issue causes libvirtd to crash in some cases.  It became more urgent with RHV upgrade to newer RHEL where libvirt started using glib and the crashes from layered products are now happening more and more often.

There are some workarounds for this in the libvirt codebase (see e.g. Bug 1894045, Bug 1931331, and their backports) but there are two issues with those:

 - the code is noticeably slower than without the workarounds
 - we are unsure if the workarounds handle all possible issues as more glib-related crashers are coming our way

Since this has been fixed upstream with https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1353 in 2.64.0, and if I recall correctly also backported to 2.62.2, possibly also some other versions, it would be really helpful to have these fixes in, especially for our layered products, be it by backporting or rebasing.

Version-Release number of selected component (if applicable):
glib2-2.56.4-8.el8.x86_64

How reproducible:
Couple of times per day with layered products such as RHV

Additional info:
Latest repetition of this is *probably* Bug 1945940, which again points to similar issue.

Comment 1 Michael Catanzaro 2021-04-13 13:08:13 UTC

Sure.

Looks like this is important enough to go to 8.4.z rather than wait for 8.5. Do you agree?

Comment 3 Michael Catanzaro 2021-04-13 13:10:15 UTC

Reading more closely, looks like you have workarounds for this already, and 8.5 will probably suffice?

Comment 4 Martin Kletzander 2021-04-14 12:40:03 UTC

8.4 would be more preferable, we are fixing the issues even in 8.3.1.z due to RHV having issues daily due to this.  Yes, we have workarounds, but they are slower.

Comment 5 Martin Kletzander 2021-04-14 12:44:48 UTC

If, however, the backport is too risky, then rebase in 8.5 will have to suffice, I hope we will not get many new bug reports until then.

Comment 11 Michael Catanzaro 2021-05-05 20:39:44 UTC

I've backported related commits from these merge requests:

https://gitlab.gnome.org/GNOME/glib/-/merge_requests/873
https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1353
https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1691

For good measure, I've also backported https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1713, which is not directly related to this issue. But I think it makes sense to sneak it in under this bug, since it is a significant fix to GMainContext, and this is a bug for fixing GMainContext.

Comment 19 errata-xmlrpc 2021-11-09 19:35:29 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 (Moderate: glib2 security and bug fix 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-2021:4385