Bug 2115342 (CVE-2022-36123)

Summary:	CVE-2022-36123 kernel: lacks a certain clear operation for the block starting symbol (.bss) cause a denial of service or gain privileges
Product:	[Other] Security Response	Reporter:	Alex <allarkin>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bdettelb, bhu, brdeoliv, chwhite, crwood, ddepaula, debarbos, dvlasenk, hdegoede, hkrzesin, hpa, jarod, jarodwilson, jburrell, jfaracco, jferlan, jforbes, jglisse, jlelli, joe.lawrence, jonathan, josef, jshortt, jstancek, jwboyer, jwyatt, kcarcia, kernel-maint, kernel-mgr, lgoncalv, linville, lzampier, masami256, mchehab, nmurray, ptalbert, qzhao, rvrbovsk, scweaver, steved, tyberry, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Linux kernel 5.19-rc8	Doc Type:	If docs needed, set a value
Doc Text:	A memory access flaw was found in the Linux kernel’s XEN hypervisor for the virtual machine. This flaw allows a local user to crash the system or potentially escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
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:	2116139, 2116140, 2116141
Bug Blocks:	2112774

Description Alex 2022-08-04 13:05:20 UTC

A flaw in Linux Kernel found in XEN (that is hypervisor for virtual machine execution that is alternative to the KVM, Kernel-based Virtual Machine).
The block starting symbol (.bss) where statically allocated variables in the .bss may not be cleared correctly, affecting XenPV guests, leading to an asm_exc_page_fault, or arbitrary code execution.
An unprivileged local attacker on the host, or guest, may potentially use this flaw.
The vulnerability is actual for the Linux kernel mainline v5.18-rc1 through v5.19-rc7.


Reference:
https://github.com/torvalds/linux/commit/96e8fc5818686d4a1591bb6907e7fdb64ef29884

Additional references:
https://github.com/torvalds/linux/commit/74a0032b8524ee2bd4443128c0bf9775928680b0
https://github.com/torvalds/linux/commit/fa1f57421e0b1c57843902c89728f823abc32f02
https://github.com/torvalds/linux/commit/8b87d8cec1b31ea710568ae49ba5f5146318da0d

Comment 2 Alex 2022-08-07 12:53:46 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2116139]

Comment 4 Justin M. Forbes 2022-08-11 12:54:35 UTC

This was fixed for Fedora with the 5.18.13 stable kernel updates.