Bug 2144960 (CVE-2022-3910)

Summary:	CVE-2022-3910 kernel: Improper update of reference count in io_uring leads to use-after-free
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
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, bhu, brdeoliv, chwhite, crwood, ddepaula, debarbos, dhoward, dvlasenk, ezulian, fhrbata, hkrzesin, jarod, jburrell, jfaracco, jferlan, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, lgoncalv, lleshchi, lzampier, nmurray, ptalbert, qzhao, rvrbovsk, scweaver, tyberry, vkumar, walters, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 6.0-rc6	Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free flaw was found in the io_uring subsystem of the Linux kernel. When io_msg_ring was invoked with a fixed file, it called io_fput_file() which improperly decreased its reference count. This could allow a local user to crash the system or escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-12-21 01:18:19 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:	2144961
Bug Blocks:	2144962

Description Pedro Sampaio 2022-11-22 19:32:52 UTC

In the Linux kernel an improper update of reference count in io_uring leads to Use-After-Free and Local Privilege Escalation. When io_msg_ring was invoked with a fixed file, it called io_fput_file() which improperly decreased its reference count. Fixed files are permanently registered to the ring, and should not be put separately.

Upstream fix:

https://kernel.dance/#fc7222c3a9f56271fba02aabbfbae999042f1679
https://github.com/torvalds/linux/commit/fc7222c3a9f56271fba02aabbfbae999042f1679

Comment 1 Justin M. Forbes 2022-11-30 19:52:19 UTC

This was fixed for Fedora with the 5.19.11 stable kernel updates.

Comment 3 Product Security DevOps Team 2022-12-21 01:18:16 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-2022-3910