LoongArch: Return NULL from huge_pte_offset() for invalid PMD
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.19 and later | 6.1.136, 6.6.89, 6.12.26, 6.14.5, 6.15 | Patch available | CNA |
- Linux VendorLinux Affected 5.19 and later Fixed in 6.1.136, 6.6.89, 6.12.26, 6.14.5, 6.15 Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.19 to before 6.1.136; 6.2 to before 6.6.89; 6.7 to before 6.12.26; 6.13 to before 6.14.5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* | 6.15 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* | 6.15 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* | 6.15 rc3 | Vulnerable | Linux |
| cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* | 11.0 | Vulnerable | Debian |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.19 to before 6.1.136; 6.2 to before 6.6.89; 6.7 to before 6.12.26; 6.13 to before 6.14.5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* Versions 6.15 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* Versions 6.15 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* Versions 6.15 rc3 Vulnerable ·Linux
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.136, 6.6.89, 6.12.26, 6.14.5, 6.15
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2025-37818
- 2026-10-03 Alias added: GHSA-4q4q-jv3m-fqjr
References
Patch 5
- https://git.kernel.org/stable/c/34256805720993e37adf6127371a1265aea8376a
- https://git.kernel.org/stable/c/2ca9380b12711afe95b3589bd82b59623b3c96b3
- https://git.kernel.org/stable/c/51424fd171cee6a33f01f7c66b8eb23ac42289d4
- https://git.kernel.org/stable/c/b49f085cd671addbda4802d6b9382513f7dd0f30
- https://git.kernel.org/stable/c/bd51834d1cf65a2c801295d230c220aeebf87a73
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- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2025-37818 · CVE Program
- CVE-2025-37818 · NVD
- FIRST EPSS
- GHSA-4q4q-jv3m-fqjr · GitHub Advisory Database · CC BY 4.0
- CVE-2025-37818 · Red Hat security data · CC BY 4.0
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