Bug 2127424 (CVE-2022-40307)

Summary:	CVE-2022-40307 kernel: use-after-free in efi_capsule_write in capsule-loader.c
Product:	[Other] Security Response	Reporter:	Mauro Matteo Cascella <mcascell>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, adscvr, airlied, alciregi, bhu, brdeoliv, bskeggs, chwhite, crwood, ddepaula, debarbos, dhoward, dvlasenk, fhrbata, 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, lleshchi, 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:	kernel 6.0-rc5	Doc Type:	If docs needed, set a value
Doc Text:	A race condition in the Linux kernel's EFI capsule loader driver was found in the way it handled write and flush operations on the device node of the EFI capsule. A local user could potentially use this flaw to crash the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-11-27 13:25:28 UTC	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:	2127425
Bug Blocks:	2125606

Description Mauro Matteo Cascella 2022-09-16 09:52:30 UTC

A race condition may occur if the user calls close() on another thread during a write() operation on the device node of the efi capsule. This is a race condition that occurs between the efi_capsule_write() and efi_capsule_flush() functions of efi_capsule_fops, which ultimately results in UAF.

Upstream commit:
https://github.com/torvalds/linux/commit/9cb636b5f6a8cc6d1b50809ec8f8d33ae0c84c95

Comment 1 Mauro Matteo Cascella 2022-09-16 09:52:58 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2127425]

Comment 4 Justin M. Forbes 2022-09-20 14:18:38 UTC

This was fixed for Fedora with the 5.19.9 stable kernel updates.

Comment 5 Product Security DevOps Team 2022-11-27 13:25:24 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2022-40307