Bug 2400780 (CVE-2022-50423)

Summary:	CVE-2022-50423 kernel: Linux kernel: Information disclosure and denial of service via use-after-free in ACPI subsystem
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	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel. This use-after-free vulnerability exists within the Advanced Configuration and Power Interface (ACPI) subsystem. A local attacker with low privileges could exploit this flaw, leading to memory corruption. This could result in information disclosure or a denial of service (DoS) on the system.	Story Points:	---
Clone Of:		Environment:
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Regression:	---	Mount Type:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-10-01 12:06:59 UTC

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

ACPICA: Fix use-after-free in acpi_ut_copy_ipackage_to_ipackage()

There is an use-after-free reported by KASAN:

  BUG: KASAN: use-after-free in acpi_ut_remove_reference+0x3b/0x82
  Read of size 1 at addr ffff888112afc460 by task modprobe/2111
  CPU: 0 PID: 2111 Comm: modprobe Not tainted 6.1.0-rc7-dirty
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
  Call Trace:
   <TASK>
   kasan_report+0xae/0xe0
   acpi_ut_remove_reference+0x3b/0x82
   acpi_ut_copy_iobject_to_iobject+0x3be/0x3d5
   acpi_ds_store_object_to_local+0x15d/0x3a0
   acpi_ex_store+0x78d/0x7fd
   acpi_ex_opcode_1A_1T_1R+0xbe4/0xf9b
   acpi_ps_parse_aml+0x217/0x8d5
   ...
   </TASK>

The root cause of the problem is that the acpi_operand_object
is freed when acpi_ut_walk_package_tree() fails in
acpi_ut_copy_ipackage_to_ipackage(), lead to repeated release in
acpi_ut_copy_iobject_to_iobject(). The problem was introduced
by "8aa5e56eeb61" commit, this commit is to fix memory leak in
acpi_ut_copy_iobject_to_iobject(), repeatedly adding remove
operation, lead to "acpi_operand_object" used after free.

Fix it by removing acpi_ut_remove_reference() in
acpi_ut_copy_ipackage_to_ipackage(). acpi_ut_copy_ipackage_to_ipackage()
is called to copy an internal package object into another internal
package object, when it fails, the memory of acpi_operand_object
should be freed by the caller.

Comment 1 Jon Moroney 2025-10-01 19:43:40 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025100155-CVE-2022-50423-5a66@gregkh/T