Bug 2127890 (CVE-2022-3176)

Summary:	CVE-2022-3176 kernel: use-after-free in io_uring for POLLFREE notification with Signalfd_poll() and binder_poll()
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, 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:		Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free flaw was found in io_uring in the Linux kernel. This flaw allows a local user to trigger the issue if a signalfd or binder fd is polled with the io_uring poll due to a lack of io_uring POLLFREE handling.	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:	2127891, 2127898, 2127899
Bug Blocks:	2127526

Description Alex 2022-09-19 10:07:02 UTC

A flaw use-after-free in io_uring in the Linux kernel found.
Local user can trigger it if a signalfd or binder fd is polled with io_uring poll, because of lack io_uring POLLFREE handling.

References:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fc78b2fc21f10c4c9c4d5d659a685710ffa63659
https://kernel.dance/#fc78b2fc21f10c4c9c4d5d659a685710ffa63659

Comment 1 Alex 2022-09-19 10:07:28 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2127891]

Comment 5 Justin M. Forbes 2022-10-04 15:02:20 UTC

This was fixed for Fedora with the 5.17.x kernel rebases.