fkie_cve-2025-37818
Vulnerability from fkie_nvd
Published
2025-05-08 07:15
Modified
2025-05-08 14:39
Severity ?
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.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Return NULL from huge_pte_offset() for invalid PMD\n\nLoongArch\u0027s huge_pte_offset() currently returns a pointer to a PMD slot\neven if the underlying entry points to invalid_pte_table (indicating no\nmapping). Callers like smaps_hugetlb_range() fetch this invalid entry\nvalue (the address of invalid_pte_table) via this pointer.\n\nThe generic is_swap_pte() check then incorrectly identifies this address\nas a swap entry on LoongArch, because it satisfies the \"!pte_present()\n\u0026\u0026 !pte_none()\" conditions. This misinterpretation, combined with a\ncoincidental match by is_migration_entry() on the address bits, leads to\nkernel crashes in pfn_swap_entry_to_page().\n\nFix this at the architecture level by modifying huge_pte_offset() to\ncheck the PMD entry\u0027s content using pmd_none() before returning. If the\nentry is invalid (i.e., it points to invalid_pte_table), return NULL\ninstead of the pointer to the slot."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: LoongArch: Devuelve NULL desde huge_pte_offset() para PMD no v\u00e1lido. La funci\u00f3n huge_pte_offset() de LoongArch actualmente devuelve un puntero a una ranura PMD incluso si la entrada subyacente apunta a invalid_pte_table (lo que indica que no hay asignaci\u00f3n). Llamadores como smaps_hugetlb_range() obtienen este valor de entrada no v\u00e1lido (la direcci\u00f3n de invalid_pte_table) a trav\u00e9s de este puntero. La comprobaci\u00f3n gen\u00e9rica is_swap_pte() identifica incorrectamente esta direcci\u00f3n como una entrada de intercambio en LoongArch, ya que cumple las condiciones \"!pte_present() \u0026amp;\u0026amp; !pte_none()\". Esta interpretaci\u00f3n err\u00f3nea, combinada con una coincidencia de is_migration_entry() en los bits de direcci\u00f3n, provoca fallos del kernel en pfn_swap_entry_to_page(). Solucione esto a nivel de arquitectura modificando huge_pte_offset() para comprobar el contenido de la entrada PMD mediante pmd_none() antes de regresar. Si la entrada no es v\u00e1lida (es decir, apunta a invalid_pte_table), devuelva NULL en lugar del puntero a la ranura."
}
],
"id": "CVE-2025-37818",
"lastModified": "2025-05-08T14:39:09.683",
"metrics": {},
"published": "2025-05-08T07:15:53.040",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2ca9380b12711afe95b3589bd82b59623b3c96b3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/34256805720993e37adf6127371a1265aea8376a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/51424fd171cee6a33f01f7c66b8eb23ac42289d4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b49f085cd671addbda4802d6b9382513f7dd0f30"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/bd51834d1cf65a2c801295d230c220aeebf87a73"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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