Bug 2087760 (CVE-2022-1786)

Summary:	CVE-2022-1786 kernel: invalid-free in io_uring that can lead to LPE
Product:	[Other] Security Response	Reporter:	Marian Rehak <mrehak>
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, bdettelb, bhu, brdeoliv, bskeggs, chwhite, crwood, ddepaula, dhoward, dvlasenk, fhrbata, fpacheco, 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, security-response-team, steved, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free flaw was found in the Linux kernel’s io_uring subsystem in the way a user sets up a ring with IORING_SETUP_IOPOLL with more than one task completing submissions on this ring. This flaw allows a local user to crash or escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-05-26 14:43:52 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:	2090718
Bug Blocks:	2087761, 2090717

Description Marian Rehak 2022-05-18 13:02:34 UTC

The root cause of the bug is a misuse of the identity model in io_uring. When preparing a request, the kernel uses the identity of the current task instead of that of the request task, which causes type confusion and invalid-free when the request is being destroyed.

Comment 6 Marian Rehak 2022-05-26 12:26:32 UTC

https://www.openwall.com/lists/oss-security/2022/05/24/4

Comment 7 Marian Rehak 2022-05-26 12:26:43 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2090718]

Comment 8 Product Security DevOps Team 2022-05-26 14:43:48 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-2022-1786

Comment 9 Justin M. Forbes 2022-05-30 16:22:49 UTC

This was fixed for Fedora with the 5.12 kernel rebases.