Bug 1226938 (CVE-2024-38384)

Summary:	VUL-0: CVE-2024-38384: kernel: blk-cgroup: fix list corruption from reorder of WRITE ->lqueued
Product:	[Novell Products] SUSE Security Incidents	Reporter:	SMASH SMASH <smash_bz>
Component:	Incidents	Assignee:	Security Team bot <security-team>
Status:	NEW ---	QA Contact:	Security Team bot <security-team>
Severity:	Normal
Priority:	P3 - Medium	CC:	mhocko, rfrohl
Version:	unspecified
Target Milestone:	---
Hardware:	Other
OS:	Other
URL:	https://smash.suse.de/issue/411979/
Whiteboard:	CVSSv3.1:SUSE:CVE-2024-38384:5.5:(AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Found By:	Security Response Team	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description SMASH SMASH 2024-06-25 08:04:43 UTC

In the Linux kernel, the following vulnerability has been resolved:

blk-cgroup: fix list corruption from reorder of WRITE ->lqueued

__blkcg_rstat_flush() can be run anytime, especially when blk_cgroup_bio_start
is being executed.

If WRITE of `->lqueued` is re-ordered with READ of 'bisc->lnode.next' in
the loop of __blkcg_rstat_flush(), `next_bisc` can be assigned with one
stat instance being added in blk_cgroup_bio_start(), then the local
list in __blkcg_rstat_flush() could be corrupted.

Fix the issue by adding one barrier.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-38384
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-38384.mbox
https://git.kernel.org/stable/c/714e59b5456e4d6e4295a9968c564abe193f461c
https://git.kernel.org/stable/c/785298ab6b802afa75089239266b6bbea590809c
https://git.kernel.org/stable/c/d0aac2363549e12cc79b8e285f13d5a9f42fd08e
https://www.cve.org/CVERecord?id=CVE-2024-38384