Bug 2193097 (CVE-2023-2513)

Summary:	CVE-2023-2513 kernel: ext4: use-after-free in ext4_xattr_set_entry()
Product:	[Other] Security Response	Reporter:	Mauro Matteo Cascella <mcascell>
Component:	vulnerability	Assignee:	Nobody <nobody>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, allarkin, bhu, chwhite, cmaiolin, dbohanno, ddepaula, debarbos, dfreiber, dvlasenk, ezulian, hkrzesin, jarod, jburrell, jdenham, jfaracco, jferlan, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, ldoskova, lgoncalv, lleshchi, lmlikith, lzampier, nmurray, ptalbert, qzhao, rogbas, rrobaina, rvrbovsk, rysulliv, scweaver, swood, tyberry, vkumar, walters, wcosta, williams, wmealing, ycote
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 6.0-rc1	Doc Type:	If docs needed, set a value
Doc Text:	A use-after-free vulnerability was found in the Linux kernel's ext4 filesystem in the way it handled the extra inode size for extended attributes. This flaw allows a privileged local user to cause a system crash or other undefined behaviors.	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:	2193101, 2193103, 2125474, 2145193, 2193102, 2193104
Bug Blocks:	2192562

Description Mauro Matteo Cascella 2023-05-04 10:18:13 UTC

A use-after-free vulnerability was found in the Linux kernel's ext4 filesystem in the way it handled extra inode size for extended attributes.

Quoting the upstream commit below: "In the calculation formula, all values except s_inode_size and i_extra_size are fixed values. When i_extra_size is the maximum value s_inode_size - EXT4_GOOD_OLD_INODE_SIZE, min_offs is -4 and free is -8. The value overflows. As a result, the preceding issue is triggered when memcpy is executed."

Patch series:
https://lore.kernel.org/all/20220616021358.2504451-1-libaokun1@huawei.com/

Upstream fix:
https://github.com/torvalds/linux/commit/67d7d8ad99be

Comment 8 Mauro Matteo Cascella 2023-06-15 18:07:35 UTC

This issue was fixed upstream in version 6.0-rc1. The kernel packages as shipped in the following Red Hat products were previously updated to a version that contains the fix via the following errata:

kernel in Red Hat Enterprise Linux 9
https://access.redhat.com/errata/RHSA-2023:2458

kernel-rt in Red Hat Enterprise Linux 9
https://access.redhat.com/errata/RHSA-2023:2148