NULL Pointer Dereference Affecting linux-virt package, versions <6.12.27-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.01% (3rd percentile)

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  • Snyk IDSNYK-MINIMOSLATEST-LINUXVIRT-13961828
  • published14 Nov 2025
  • disclosed8 May 2025

Introduced: 8 May 2025

CVE-2025-37818  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Minimos:latest linux-virt to version 6.12.27-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-virt package and not the linux-virt package as distributed by Minimos. See How to fix? for Minimos:latest relevant fixed versions and status.

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

LoongArch: Return NULL from huge_pte_offset() for invalid PMD

LoongArch's huge_pte_offset() currently returns a pointer to a PMD slot even if the underlying entry points to invalid_pte_table (indicating no mapping). Callers like smaps_hugetlb_range() fetch this invalid entry value (the address of invalid_pte_table) via this pointer.

The generic is_swap_pte() check then incorrectly identifies this address as a swap entry on LoongArch, because it satisfies the "!pte_present() && !pte_none()" conditions. This misinterpretation, combined with a coincidental match by is_migration_entry() on the address bits, leads to kernel crashes in pfn_swap_entry_to_page().

Fix this at the architecture level by modifying huge_pte_offset() to check the PMD entry's content using pmd_none() before returning. If the entry is invalid (i.e., it points to invalid_pte_table), return NULL instead of the pointer to the slot.

CVSS Base Scores

version 3.1