CVE-2026-97943
In the Linux kernel, the following vulnerability has been resolved:
x86/mm/pat: Acquire init_mm write lock on collapse to avoid UAF
x86 implements page attribute modification using its Change Page Attributes (CPA) mechanism.
This tracks properties of ranges such as cache mode through x86 page attributes, and as part of that logic manipulates kernel page tables.
Since commit:
ranges of kernel page table entries can be collapsed into huge page table entries as part of this logic.
As part of this collapse, it frees the page tables which the collapsed entries previously pointed to, and it does so without any relevant locks being held to preclude concurrent kernel page table walkers.
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The only way this code can be reached is if CPA_COLLAPSE is specified, and this is only set in set_memory_rox() via:
set_memory_rox() -> change_page_attr_set_clr() -> cpa_flush() -> cpa_collapse_large_pages()
Notable users of this are execmem and BPF when manipulating executable mappings.
However, this is problematic for ptdump as it walks ranges it does not own and thus runs the risk of a use-after-free on page tables freed underneath it.
In addition, concurrent CPA collapse operations are possible which can also cause races.
Resolve the issue by acquiring the mmap write lock on init_mm across the whole operation.
It is safe to acquire a sleeping lock as all the callers invoke set_memory_rox() from process context and in any case, change_page_attr_set_clr() calls vm_unmap_alias() which ultimately takes a mutex, disallowing atomic context here.
Detalles técnicos trazas, registros y código del informe original
41d88484c71c ("x86/mm/pat: restore large ROX pages after fragmentation")CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.20%
- Percentil entre todas las CVEs puntuadas: 9
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-97943",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "41d88484c71cd4f659348da41b7b5b3dbd3be1f6",
"lessThan": "35820cf8dd521f5a651e221483015b0586794516",
"versionType": "git"
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{
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{
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"versionType": "git"
}
],
"programFiles": [
"arch/x86/mm/pat/set_memory.c",
"include/linux/mmap_lock.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc4",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/x86/mm/pat/set_memory.c",
"include/linux/mmap_lock.h"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-25T11:17:21.750",
"references": [
{
"url": "https://git.kernel.org/stable/c/35820cf8dd521f5a651e221483015b0586794516",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/93b98882198b15bd482da1fe8e84b05c7c3b3d83",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a1c7570cedd03372812a5b693732880867babbca",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm/pat: Acquire init_mm write lock on collapse to avoid UAF\n\nx86 implements page attribute modification using its Change Page\nAttributes (CPA) mechanism.\n\nThis tracks properties of ranges such as cache mode through x86 page\nattributes, and as part of that logic manipulates kernel page tables.\n\nSince commit:\n\n 41d88484c71c (\"x86/mm/pat: restore large ROX pages after fragmentation\")\n\nranges of kernel page table entries can be collapsed into\nhuge page table entries as part of this logic.\n\nAs part of this collapse, it frees the page tables which the collapsed\nentries previously pointed to, and it does so without any relevant locks\nbeing held to preclude concurrent kernel page table walkers.\n\nThe only way this code can be reached is if CPA_COLLAPSE is specified, and\nthis is only set in set_memory_rox() via:\n\nset_memory_rox()\n-> change_page_attr_set_clr()\n-> cpa_flush()\n-> cpa_collapse_large_pages()\n\nNotable users of this are execmem and BPF when manipulating executable\nmappings.\n\nHowever, this is problematic for ptdump as it walks ranges it does not own\nand thus runs the risk of a use-after-free on page tables freed underneath\nit.\n\nIn addition, concurrent CPA collapse operations are possible which can also\ncause races.\n\nResolve the issue by acquiring the mmap write lock on init_mm across the\nwhole operation.\n\nIt is safe to acquire a sleeping lock as all the callers invoke\nset_memory_rox() from process context and in any case,\nchange_page_attr_set_clr() calls vm_unmap_alias() which ultimately takes a\nmutex, disallowing atomic context here."
}
],
"lastModified": "2026-09-25T11:17:21.750",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}