IM
IronMonkey Threat Research

CVE-2025-39845 MEDIUM

Published: 2025-09-19 | Last Modified: 2026-07-14 | Status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: x86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() Define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure page tables are properly synchronized when calling p*d_populate_kernel(). For 5-level paging, synchronization is performed via pgd_populate_kernel(). In 4-level paging, pgd_populate() is a no-op, so synchronization is instead performed at the P4D level via p4d_populate_kernel(). This fixes intermittent boot failures on systems using 4-level paging and a large amount of persistent memory: BUG: unable to handle page fault for address: ffffe70000000034 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI RIP: 0010:__init_single_page+0x9/0x6d Call Trace: <TASK> __init_zone_device_page+0x17/0x5d memmap_init_zone_device+0x154/0x1bb pagemap_range+0x2e0/0x40f memremap_pages+0x10b/0x2f0 devm_memremap_pages+0x1e/0x60 dev_dax_probe+0xce/0x2ec [device_dax] dax_bus_probe+0x6d/0xc9 [... snip ...] </TASK> It also fixes a crash in vmemmap_set_pmd() caused by accessing vmemmap before sync_global_pgds() [1]: BUG: unable to handle page fault for address: ffffeb3ff1200000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI Tainted: [W]=WARN RIP: 0010:vmemmap_set_pmd+0xff/0x230 <TASK> vmemmap_populate_hugepages+0x176/0x180 vmemmap_populate+0x34/0x80 __populate_section_memmap+0x41/0x90 sparse_add_section+0x121/0x3e0 __add_pages+0xba/0x150 add_pages+0x1d/0x70 memremap_pages+0x3dc/0x810 devm_memremap_pages+0x1c/0x60 xe_devm_add+0x8b/0x100 [xe] xe_tile_init_noalloc+0x6a/0x70 [xe] xe_device_probe+0x48c/0x740 [xe] [... snip ...]

CVSS Metrics

Base Score: 5.5 (MEDIUM)

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

Attack VectorLOCAL
Attack ComplexityLOW
Privileges RequiredLOW
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactNONE
Integrity ImpactNONE
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 1.8

Impact Score: 3.6

Weaknesses

Source Type Description
[email protected] Primary
en CWE-401

Affected Products

Vendor Product Version Update Type
linux linux_kernel * <built-in method update of dict object at 0x702ba70f4d80> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bdc0d1540> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702ba6ab5540> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bcbbf4e40> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bdc0d3bc0> Operating System
linux linux_kernel 6.17 <built-in method update of dict object at 0x702bdc0d3840> Operating System
linux linux_kernel 6.17 <built-in method update of dict object at 0x702ba70f7dc0> Operating System
linux linux_kernel 6.17 <built-in method update of dict object at 0x702bcbbf6e80> Operating System
linux linux_kernel 6.17 <built-in method update of dict object at 0x702bdc0d2e80> Operating System
debian debian_linux 11.0 <built-in method update of dict object at 0x702ba7d67e00> Operating System

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References

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