Bug 2300480 (CVE-2024-41084)

Summary:	CVE-2024-41084 kernel: cxl/region: Avoid null pointer dereference in region lookup
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 6.6.37, kernel 6.9.8, kernel 6.10	Doc Type:	If docs needed, set a value
Doc Text:		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:	2301665
Bug Blocks:

Description OSIDB Bzimport 2024-07-29 16:20:42 UTC

In the Linux kernel, the following vulnerability has been resolved:

cxl/region: Avoid null pointer dereference in region lookup

cxl_dpa_to_region() looks up a region based on a memdev and DPA.
It wrongly assumes an endpoint found mapping the DPA is also of
a fully assembled region. When not true it leads to a null pointer
dereference looking up the region name.

This appears during testing of region lookup after a failure to
assemble a BIOS defined region or if the lookup raced with the
assembly of the BIOS defined region.

Failure to clean up BIOS defined regions that fail assembly is an
issue in itself and a fix to that problem will alleviate some of
the impact. It will not alleviate the race condition so let's harden
this path.

The behavior change is that the kernel oops due to a null pointer
dereference is replaced with a dev_dbg() message noting that an
endpoint was mapped.

Additional comments are added so that future users of this function
can more clearly understand what it provides.

Comment 1 Mauro Matteo Cascella 2024-07-30 15:03:05 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024072951-CVE-2024-41084-c144@gregkh/T

Comment 2 Mauro Matteo Cascella 2024-07-30 15:03:27 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2301665]

Comment 7 errata-xmlrpc 2024-11-12 09:37:18 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2024:9315 https://access.redhat.com/errata/RHSA-2024:9315