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.
Metrics
Affected Vendors & Products
References
History
Tue, 15 Jul 2025 13:45:00 +0000
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Fri, 09 May 2025 02:15:00 +0000
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cvssV3_1
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Thu, 08 May 2025 06:45:00 +0000
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Description | 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. | |
Title | LoongArch: Return NULL from huge_pte_offset() for invalid PMD | |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-26T05:21:32.260Z
Reserved: 2025-04-16T04:51:23.947Z
Link: CVE-2025-37818

No data.

Status : Awaiting Analysis
Published: 2025-05-08T07:15:53.040
Modified: 2025-05-08T14:39:09.683
Link: CVE-2025-37818


No data.