Bug 2196759 (CVE-2023-2236)

Summary:	CVE-2023-2236 kernel: use-after-free in io_uring/filetable in io_install_fixed_file
Product:	[Other] Security Response	Reporter:	Rohit Keshri <rkeshri>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	acaringi, allarkin, bhu, chwhite, crwood, dbohanno, ddepaula, debarbos, dfreiber, dvlasenk, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jferlan, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, ldoskova, lgoncalv, lzampier, nmurray, ptalbert, qzhao, rogbas, rrobaina, rvrbovsk, scweaver, vkumar, walters, wcosta, williams, wmealing, ycote
Target Milestone:	---	Keywords:	Reopened, Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	Kernel 6.1-rc7	Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free vulnerability was found in io_install_fixed_file in io_uring/filetable.c in the Linux Kernel’s io_uring subsystem. This flaw allows an attacker to achieve local privilege escalation.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-05-31 19:15:58 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:	2068237, 2210986, 2210987
Bug Blocks:	2192393

Description Rohit Keshri 2023-05-10 06:58:12 UTC

A use-after-free vulnerability in the Linux Kernel io_uring subsystem can be exploited to achieve local privilege escalation.

Both io_install_fixed_file and its callers call fput in a file in case of an error, causing a reference underflow which leads to a use-after-free vulnerability.

We recommend upgrading past commit 9d94c04c0db024922e886c9fd429659f22f48ea4.

https://kernel.dance/9d94c04c0db024922e886c9fd429659f22f48ea4
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9d94c04c0db024922e886c9fd429659f22f48ea4

Comment 2 Rohit Keshri 2023-05-10 07:29:05 UTC

There was no shipped kernel version were seen affected with this problem. These files are not built in our source code.

Comment 5 Product Security DevOps Team 2023-05-10 12:44:23 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-2023-2236