CVE-2025-38344 [Medium] | Information Disclosure in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: ACPICA: fix acpi parse and parseext cache leaks ACPICA commit 8829e70e1360c81e7a5a901b5d4f48330e021ea5 I'm Seunghun Han, and I work for National Security Research Institute of South Korea. I have been doing a research on ACPI and found an ACPI cache leak in ACPI early abort cases. Boot log of ACPI cache leak is as follows: [ 0.352414] ACPI: Added _OSI(Module Device) [ 0.353182] ACPI: Added _OSI(Processor Device) [ 0.353182] ACPI: Added _OSI(3.0 _SCP Extensions) [ 0.353182] ACPI: Added _OSI(Processor Aggregator Device) [ 0.356028] ACPI: Unable to start the ACPI Interpreter [ 0.356799] ACPI Error: Could not remove SCI handler (20170303/evmisc-281) [ 0.360215] kmem_cache_destroy Acpi-State: Slab cache still has objects [ 0.360648] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 4.12.0-rc4-next-20170608+ #10 [ 0.361273] Hardware name: innotek gmb_h virtual_box/virtual_box, BIOS virtual_box 12/01/2006 [ 0.361873] Call Trace: [ 0.362243] ? dump_stack+0x5c/0x81 [ 0.362591] ? kmem_cache_destroy+0x1aa/0x1c0 [ 0.362944] ? acpi_sleep_proc_init+0x27/0x27 [ 0.363296] ? acpi_os_delete_cache+0xa/0x10 [ 0.363646] ? acpi_ut_delete_caches+0x6d/0x7b [ 0.364000] ? acpi_terminate+0xa/0x14 [ 0.364000] ? acpi_init+0x2af/0x34f [ 0.364000] ? __class_create+0x4c/0x80 [ 0.364000] ? video_setup+0x7f/0x7f [ 0.364000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.364000] ? do_one_initcall+0x4e/0x1a0 [ 0.364000] ? kernel_init_freeable+0x189/0x20a [ 0.364000] ? rest_init+0xc0/0xc0 [ 0.364000] ? kernel_init+0xa/0x100 [ 0.364000] ? ret_from_fork+0x25/0x30 I analyzed this memory leak in detail. I found that “Acpi-State” cache and “Acpi-Parse” cache were merged because the size of cache objects was same slab cache size. I finally found “Acpi-Parse” cache and “Acpi-parse_ext” cache were leaked using SLAB_NEVER_MERGE flag in kmem_cache_create() function. Real ACPI cache leak point is as follows: [ 0.360101] ACPI: Added _OSI(Module Device) [ 0.360101] ACPI: Added _OSI(Processor Device) [ 0.360101] ACPI: Added _OSI(3.0 _SCP Extensions) [ 0.361043] ACPI: Added _OSI(Processor Aggregator Device) [ 0.364016] ACPI: Unable to start the ACPI Interpreter [ 0.365061] ACPI Error: Could not remove SCI handler (20170303/evmisc-281) [ 0.368174] kmem_cache_destroy Acpi-Parse: Slab cache still has objects [ 0.369332] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 4.12.0-rc4-next-20170608+ #8 [ 0.371256] Hardware name: innotek gmb_h virtual_box/virtual_box, BIOS virtual_box 12/01/2006 [ 0.372000] Call Trace: [ 0.372000] ? dump_stack+0x5c/0x81 [ 0.372000] ? kmem_cache_destroy+0x1aa/0x1c0 [ 0.372000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.372000] ? acpi_os_delete_cache+0xa/0x10 [ 0.372000] ? acpi_ut_delete_caches+0x56/0x7b [ 0.372000] ? acpi_terminate+0xa/0x14 [ 0.372000] ? acpi_init+0x2af/0x34f [ 0.372000] ? __class_create+0x4c/0x80 [ 0.372000] ? video_setup+0x7f/0x7f [ 0.372000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.372000] ? do_one_initcall+0x4e/0x1a0 [ 0.372000] ? kernel_init_freeable+0x189/0x20a [ 0.372000] ? rest_init+0xc0/0xc0 [ 0.372000] ? kernel_init+0xa/0x100 [ 0.372000] ? ret_from_fork+0x25/0x30 [ 0.388039] kmem_cache_destroy Acpi-parse_ext: Slab cache still has objects [ 0.389063] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 4.12.0-rc4-next-20170608+ #8 [ 0.390557] Hardware name: innotek gmb_h virtual_box/virtual_box, BIOS virtual_box 12/01/2006 [ 0.392000] Call Trace: [ 0.392000] ? dump_stack+0x5c/0x81 [ 0.392000] ? kmem_cache_destroy+0x1aa/0x1c0 [ 0.392000] ? acpi_sleep_proc_init+0x27/0x27 [ 0.392000] ? acpi_os_delete_cache+0xa/0x10 [ 0.392000] ? acpi_ut_delete_caches+0x6d/0x7b [ 0.392000] ? acpi_terminate+0xa/0x14 [ 0.392000] ? acpi_init+0x2af/0x3 ---truncated---

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-05-06	0.04%	0.05%	+0.01%
2	2025-12-06	0.06%	0.04%	-0.02%
3	2025-11-09	—	0.06%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-05-06

0.04%

0.05%

+0.01%

2025-12-06

0.06%

0.04%

-0.02%

2025-11-09

—

0.06%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.5

3.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

[email protected]

OS Trackers for CVE-2025-38344

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2025-38344 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6.	https://security-tracker.debian.org/tracker/CVE-2025-38344
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2025-38344
`suse`	medium	CVE-2025-38344 severity moderate: SUSE including 473 source package names (2.1.3-6.67:kernel-default-base-6.4.0-32.1.21.10, 2.1.3-7.44:kernel-default-6.4.0-32.1, …), 927 product×package rows across 184 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (184 product lines)): Fixed 627, Known Affected 231, Known Not Affected 29, First Fixed 21, Will Not Fix 19.	https://www.suse.com/security/cve/CVE-2025-38344/
`ubuntu`	medium	CVE-2025-38344 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1548 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1142, released 170, ignored 168, needed 45, not-affected 20, needs-triage 2, pending 1.	https://ubuntu.com/security/CVE-2025-38344

Affected software / configurations for CVE-2025-38344

Vendor	Product	Version	Raw CPE
linux	linux_kernel	< 5.4.295	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.5, < 5.10.239	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.186	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.1.142	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.2, < 6.6.95	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.35	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.15.4	cpe:2.3:o:linux:linux_kernel::::::::
debian	debian_linux	11.0	cpe:2.3:o:debian:debian_linux:11.0:::::::*

References for CVE-2025-38344

URL	Tags
https://git.kernel.org/stable/c/0a119fdaed67566aa3e0b5222dced4d08bbce463	Patch
https://git.kernel.org/stable/c/198c2dab022e5e94a99fff267b669d693bc7bb49	Patch
https://git.kernel.org/stable/c/1e0e629e88b1f7751ce69bf70cda6d1598d45271	Patch
https://git.kernel.org/stable/c/1fee4324b5660de080cefc3fc91c371543bdb8f6	Patch
https://git.kernel.org/stable/c/3e0c59180ec83bdec43b3d3482cff23d86d380d0	Patch
https://git.kernel.org/stable/c/41afebc9a0762aafc35d2df88f4e1b798155a940	Patch
https://git.kernel.org/stable/c/960236150cd3f08e13b397dd5ae4ccf7a2986c00	Patch
https://git.kernel.org/stable/c/bed18f0bdcd6737a938264a59d67923688696fc4	Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html	Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html	Third Party Advisory

URL

CVE-2025-38344 | ACPICA: fix acpi parse and parseext cache leaks

Exploit prediction scoring system (EPSS) score for CVE-2025-38344

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38344

Weakness enumeration for CVE-2025-38344

OS Trackers for CVE-2025-38344

Affected software / configurations for CVE-2025-38344

References for CVE-2025-38344