Bug 2363457 (CVE-2022-49894)

Summary:	CVE-2022-49894 kernel: cxl/region: Fix region HPA ordering validation
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-05-01 15:05:21 UTC

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

cxl/region: Fix region HPA ordering validation

Some regions may not have any address space allocated. Skip them when
validating HPA order otherwise a crash like the following may result:

 devm_cxl_add_region: cxl_acpi cxl_acpi.0: decoder3.4: created region9
 BUG: kernel NULL pointer dereference, address: 0000000000000000
 [..]
 RIP: 0010:store_targetN+0x655/0x1740 [cxl_core]
 [..]
 Call Trace:
  <TASK>
  kernfs_fop_write_iter+0x144/0x200
  vfs_write+0x24a/0x4d0
  ksys_write+0x69/0xf0
  do_syscall_64+0x3a/0x90

store_targetN+0x655/0x1740:
alloc_region_ref at drivers/cxl/core/region.c:676
(inlined by) cxl_port_attach_region at drivers/cxl/core/region.c:850
(inlined by) cxl_region_attach at drivers/cxl/core/region.c:1290
(inlined by) attach_target at drivers/cxl/core/region.c:1410
(inlined by) store_targetN at drivers/cxl/core/region.c:1453

Comment 1 Avinash Hanwate 2025-05-02 05:22:11 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025050159-CVE-2022-49894-bc10@gregkh/T