CVE-2025-38345
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-07-10

Last updated on: 2025-12-16

Assigner: kernel.org

Description
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.
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Meta Information
Published
2025-07-10
Last Modified
2025-12-16
Generated
2026-05-07
AI Q&A
2025-07-10
EPSS Evaluated
2026-05-05
NVD
CVE-2025-38345
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 5.11 (inc) to 5.15.186 (inc)
debian debian_linux 11.0
linux kernel 4.12.0-rc5
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-401 The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is an ACPI operand cache memory leak in the Linux kernel's ACPICA component. It occurs when the kernel encounters a malicious ACPI table causing early termination of ACPI functions during boot. Due to a miscalculation in stack handling functions, the kernel leaks memory from the ACPI operand cache. This leak can expose kernel memory locations in stack dumps, potentially aiding attackers in bypassing kernel address space layout randomization (ASLR).


How can this vulnerability impact me? :

The vulnerability can lead to exposure of kernel memory addresses through stack dumps during boot. Malicious users could exploit this information to defeat kernel ASLR, which is a security mechanism designed to prevent certain types of attacks. This could increase the risk of privilege escalation or other kernel-level attacks.


How can this vulnerability be detected on my network or system? Can you suggest some commands?

This vulnerability can be detected by examining the system boot logs for specific ACPI error messages indicating an ACPI operand cache leak. Look for log entries similar to: 'kmem_cache_destroy Acpi-Operand: Slab cache still has objects' and other ACPI errors such as 'ACPI Error: Illegal I/O port address/length above 64K' or 'ACPI Exception: AE_LIMIT'. You can check the kernel boot log using commands like 'dmesg | grep -i acpi' or 'journalctl -k | grep -i acpi' to find these messages.


What immediate steps should I take to mitigate this vulnerability?

The immediate mitigation step is to update the Linux kernel to a version that includes the patch fixing the ACPI operand cache leak (post kernel version 4.9). Applying the patch that corrects the acpi_ds_obj_stack_pop_and_delete() function to properly manage the operand cache will prevent the memory leak and associated security risks. Until then, monitoring logs for the described ACPI errors and restricting access to the system to trusted users can reduce exploitation risk.


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