Bug 2177862 (CVE-2022-2503)

Summary:	CVE-2022-2503 kernel: LoadPin bypass via dm-verity table reload
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, agk, allarkin, bhu, chwhite, ddepaula, debarbos, dfreiber, dvlasenk, ezulian, fhrbata, hkrzesin, jarod, jburrell, jfaracco, jferlan, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, lgoncalv, lleshchi, lzampier, nmurray, ptalbert, qzhao, rogbas, rvrbovsk, scweaver, swood, tyberry, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Kernel 5.19 RC1	Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in the Linux kernel. Dm-verity is used for extending root-of-trust to root filesystems. LoadPin builds on this property to restrict module and firmware loads to just the trusted root filesystem. Device-mapper table reloads currently allow users with root privileges to switch out the target with an equivalent dm-linear target and bypass verification until reboot. This allows root to bypass LoadPin and can be used to load untrusted and unverified kernel modules and firmware, which implies arbitrary kernel execution and persistence for peripherals that do not verify firmware updates.	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:	2177893, 2177894, 2177895, 2177896, 2177899, 2177900, 2183114, 2183116, 2012340, 2183115, 2183117
Bug Blocks:	2177863

Description Pedro Sampaio 2023-03-13 17:50:17 UTC

Dm-verity is used for extending root-of-trust to root filesystems. LoadPin builds on this property to restrict module/firmware loads to just the trusted root filesystem. Device-mapper table reloads currently allow users with root privileges to switch out the target with an equivalent dm-linear target and bypass verification till reboot. This allows root to bypass LoadPin and can be used to load untrusted and unverified kernel modules and firmware, which implies arbitrary kernel execution and persistence for peripherals that do not verify firmware updates. We recommend upgrading past commit 4caae58406f8ceb741603eee460d79bacca9b1b5

https://github.com/google/security-research/security/advisories/GHSA-6vq3-w69p-w63m
https://security.netapp.com/advisory/ntap-20230214-0005/