Cloudanix VulnDB

CVE-2025-38345

None

CVSS

—

EPSS

0.2%

Published

Jul 10, 2025

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A flaw in the Linux kernel's handling of power-management tables can leak internal memory addresses during startup errors, making it easier for attackers to break memory protections on older systems.

Chainable
Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Low
Impact
Data Exposure
Component
OS kernel
Class
Information Disclosure
Remediation
Patch
Effort
Low
Patch risk
Low

What it actually does

Miscalculation of operand stack index in acpi_ds_obj_stack_pop_and_delete versus push allows ACPI operand objects to remain referenced after early interpreter termination triggered by malformed ACPI tables, producing a kmem_cache leak and exposing kernel function addresses in stack dumps on kernels <= 4.9.

Why it matters to the business

On unpatched older LTS kernels the leak supplies kernel address information that weakens ASLR, raising the success rate of subsequent kernel exploits; prevalence across Linux distributions and 474-day publication window indicate broad exposure without immediate ransomware or KEV usage.

How an attack unfolds

An attacker supplies a malicious ACPI table that forces interpreter initialization failure; the resulting early termination path triggers the operand-stack accounting error, leaving cache objects and emitting a stack trace containing kernel addresses that can be harvested to defeat ASLR in later privilege-escalation attempts by the same or related campaigns.

How to fix it

Upgrade linux-lts to 6.6.58-r0 or 6.12.41-r0; apply mainline commit 4fa430a8bca708c7776f6b9d001257f48b19a5b7 or later; rebuild and reboot systems that embed the vulnerable ACPICA code.

How to confirm the fix worked

Verify running kernel contains the fix commit or package version 6.6.58-r0/6.12.41-r0; attempt boot with a deliberately malformed ACPI table and confirm absence of both the Acpi-Operand cache-leak message and kernel-symbol disclosure in logs.

Typical attack path

  1. Deliver malicious ACPI table via firmware or hypervisor
  2. Trigger ACPI initialization during early boot
  3. Force AE_LIMIT or similar error causing acpi_terminate
  4. Observe kmem_cache_destroy leak and stack dump containing kernel symbols
  5. Reuse disclosed addresses to bypass ASLR in follow-on exploits

How to detect it

Search kernel boot logs and dmesg for the exact phrases 'kmem_cache_destroy Acpi-Operand: Slab cache still has objects' together with preceding ACPI Error messages about illegal I/O port addresses or AE_LIMIT exceptions; correlate with early-termination paths in acpi_init.

  • kmem_cache_destroy Acpi-Operand: Slab cache still has objects
  • ACPI Error: Illegal I/O port address/length above 64K
  • ACPI Exception: AE_LIMIT, Unable to initialize fixed events
  • ACPI Error: Could not remove SCI handler

What your security team should do

  • Patch all systems to the listed fixed versions within 30 days
  • Add boot-time ACPI error and kmem_cache_destroy monitoring to SIEM
  • Review firmware update processes to reduce malicious table exposure
  • Harden older kernels with additional ASLR or symbol-hidden builds until patched

The record

In the Linux kernel, the following vulnerability has been resolved: ACPICA: fix acpi operand cache leak in dswstate.c ACPICA commit 987a3b5cf7175916e2a4b6ea5b8e70f830dfe732 I found an ACPI cache leak in ACPI early termination and boot continuing case. When early termination occurs due to malicious ACPI table, Linux kernel terminates ACPI function and continues to boot process. While kernel terminates ACPI function, kmem_cache_destroy() reports Acpi-Operand cache leak. Boot log of ACPI operand cache leak is as follows: >[ 0.585957] ACPI: Added _OSI(Module Device) >[ 0.587218] ACPI: Added _OSI(Processor Device) >[ 0.588530] ACPI: Added _OSI(3.0 _SCP Extensions) >[ 0.589790] ACPI: Added _OSI(Processor Aggregator Device) >[ 0.591534] ACPI Error: Illegal I/O port address/length above 64K: C806E00000004002/0x2 (20170303/hwvalid-155) >[ 0.594351] ACPI Exception: AE_LIMIT, Unable to initialize fixed events (20170303/evevent-88) >[ 0.597858] ACPI: Unable to start the ACPI Interpreter >[ 0.599162] ACPI Error: Could not remove SCI handler (20170303/evmisc-281) >[ 0.601836] kmem_cache_destroy Acpi-Operand: Slab cache still has objects >[ 0.603556] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc5 #26 >[ 0.605159] Hardware name: innotek gmb_h virtual_box/virtual_box, BIOS virtual_box 12/01/2006 >[ 0.609177] Call Trace: >[ 0.610063] ? dump_stack+0x5c/0x81 >[ 0.611118] ? kmem_cache_destroy+0x1aa/0x1c0 >[ 0.612632] ? acpi_sleep_proc_init+0x27/0x27 >[ 0.613906] ? acpi_os_delete_cache+0xa/0x10 >[ 0.617986] ? acpi_ut_delete_caches+0x3f/0x7b >[ 0.619293] ? acpi_terminate+0xa/0x14 >[ 0.620394] ? acpi_init+0x2af/0x34f >[ 0.621616] ? __class_create+0x4c/0x80 >[ 0.623412] ? video_setup+0x7f/0x7f >[ 0.624585] ? acpi_sleep_proc_init+0x27/0x27 >[ 0.625861] ? do_one_initcall+0x4e/0x1a0 >[ 0.627513] ? kernel_init_freeable+0x19e/0x21f >[ 0.628972] ? rest_init+0x80/0x80 >[ 0.630043] ? kernel_init+0xa/0x100 >[ 0.631084] ? ret_from_fork+0x25/0x30 >[ 0.633343] vgaarb: loaded >[ 0.635036] EDAC MC: Ver: 3.0.0 >[ 0.638601] PCI: Probing PCI hardware >[ 0.639833] PCI host bridge to bus 0000:00 >[ 0.641031] pci_bus 0000:00: root bus resource [io 0x0000-0xffff] > ... Continue to boot and log is omitted ... I analyzed this memory leak in detail and found acpi_ds_obj_stack_pop_and_ delete() function miscalculated the top of the stack. acpi_ds_obj_stack_push() function uses walk_state->operand_index for start position of the top, but acpi_ds_obj_stack_pop_and_delete() function considers index 0 for it. Therefore, this causes acpi operand memory leak. This cache leak causes a security threat because an old kernel (<= 4.9) shows memory locations of kernel functions in stack dump. Some malicious users could use this information to neutralize kernel ASLR. I made a patch to fix ACPI operand cache leak.

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux 0 No fix
Debian:12 linux 0 No fix
Debian:13 linux 0 6.12.35-1
Debian:14 linux 0 6.12.35-1
Linux Kernel 0 5.4.295
Linux Kernel 2.6.26 5.4.295
Mageia:9 kernel 0 6.6.101-1.mga9
Mageia:9 kernel-linus 0 6.6.101-1.mga9
Mageia:9 kmod-virtualbox 0 7.1.10-7.mga9
Mageia:9 kmod-xtables-addons 0 3.24-83.mga9
Mageia:9 wireless-regdb 0 20250710-1.mga9
SUSE:Linux Enterprise High Availability Extension 15 SP6 kernel-default 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-default 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_14 0 1-150600.1.5.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_14 0 1-150600.13.3.4
SUSE:Linux Enterprise Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_3 0 1-150700.1.5.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-64kb 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default-base 0 6.4.0-150600.23.65.1.150600.12.28.4
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-source 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-zfcpdump 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco 0 6.4.0-15061.28.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco_debug 0 6.4.0-15061.28.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-source-coco 0 6.4.0-15061.28.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-syms-coco 0 6.4.0-15061.28.coco15sp6.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-docs 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-obs-build 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-source 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-syms 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Legacy 15 SP6 kernel-default 0 6.4.0-150600.23.65.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-azure 0 6.4.0-150600.8.48.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure 0 6.4.0-150600.8.48.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-syms-azure 0 6.4.0-150600.8.48.1
SUSE:Linux Enterprise Workstation Extension 15 SP6 kernel-default 0 6.4.0-150600.23.65.1
SUSE:Real Time Module 15 SP6 kernel-rt 0 6.4.0-150600.10.49.1
SUSE:Real Time Module 15 SP6 kernel-rt_debug 0 6.4.0-150600.10.49.1
SUSE:Real Time Module 15 SP6 kernel-source-rt 0 6.4.0-150600.10.49.1
SUSE:Real Time Module 15 SP6 kernel-syms-rt 0 6.4.0-150600.10.49.1
SUSE:Real Time Module 15 SP7 kernel-rt 0 6.4.0-150700.7.13.1
SUSE:Real Time Module 15 SP7 kernel-source-rt 0 6.4.0-150700.7.13.1
SUSE:Real Time Module 15 SP7 kernel-syms-rt 0 6.4.0-150700.7.13.1
openSUSE:Leap 15.6 dtb-aarch64 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-64kb 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-azure 0 6.4.0-150600.8.48.1
openSUSE:Leap 15.6 kernel-debug 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-default 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-default-base 0 6.4.0-150600.23.65.1.150600.12.28.4
openSUSE:Leap 15.6 kernel-docs 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-kvmsmall 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-obs-build 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-obs-qa 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-rt 0 6.4.0-150600.10.49.1
openSUSE:Leap 15.6 kernel-rt_debug 0 6.4.0-150600.10.49.1
openSUSE:Leap 15.6 kernel-source 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-source-azure 0 6.4.0-150600.8.48.1
openSUSE:Leap 15.6 kernel-source-rt 0 6.4.0-150600.10.49.1
openSUSE:Leap 15.6 kernel-syms 0 6.4.0-150600.23.65.1
openSUSE:Leap 15.6 kernel-syms-azure 0 6.4.0-150600.8.48.1
openSUSE:Leap 15.6 kernel-syms-rt 0 6.4.0-150600.10.49.1
openSUSE:Leap 15.6 kernel-zfcpdump 0 6.4.0-150600.23.65.1
openSUSE:Leap 16.0 dtb-aarch64 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-64kb 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-default 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-default-base 0 6.12.0-160000.6.1.160000.2.4
openSUSE:Leap 16.0 kernel-docs 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-kvmsmall 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-obs-build 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-obs-qa 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-rt 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-source 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-syms 0 6.12.0-160000.6.1
openSUSE:Leap 16.0 kernel-zfcpdump 0 6.12.0-160000.6.1

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