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linux — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2023-52935

In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: fix ->anon_vma race If an ->anon_vma is attached to the VMA, collapse_and_free_pmd() requires it to be locked. Page table traversal is allowed under any one of the mmap lock, the anon_vma lock (if the VMA is associated with an anon_vma), and the mapping lock (if the VMA is associated with a mapping); and so to be able to remove page tables, we must hold all three of them. retract_page_tables() bails out if an ->anon_vma is attached, but does this check before holding the mmap lock (as the comment above the check explains). If we racily merged an existing ->anon_vma (shared with a child process) from a neighboring VMA, subsequent rmap traversals on pages belonging to the child will be able to see the page tables that we are concurrently removing while assuming that nothing else can access them. Repeat the ->anon_vma check once we hold the mmap lock to ensure that there really is no concurrent page table access. Hitting this bug causes a lockdep warning in collapse_and_free_pmd(), in the line "lockdep_assert_held_write(&vma->anon_vma->root->rwsem)". It can also lead to use-after-free access.

Products
linux
Affected versions
Not specified
Fixed versions
6.1.11-1
CVEs
CVE-2023-52935
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 16:07 UTC · Revision 1

Source evidence

DEBIAN-CVE-2023-52935

core-osv · Original source

Published 27 Mar 2025, 17:15 UTC

In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: fix ->anon_vma race If an ->anon_vma is attached to the VMA, collapse_and_free_pmd() requires it to be locked. Page table traversal is allowed under any one of the mmap lock, the anon_vma lock (if the VMA is associated with an anon_vma), and the mapping lock (if the VMA is associated with a mapping); and so to be able to remove page tables, we must hold all three of them. retract_page_tables() bails out if an ->anon_vma is attached, but does this check before holding the mmap lock (as the comment above the check explains). If we racily merged an existing ->anon_vma (shared with a child process) from a neighboring VMA, subsequent rmap traversals on pages belonging to the child will be able to see the page tables that we are concurrently removing while assuming that nothing else can access them. Repeat the ->anon_vma check once we hold the mmap lock to ensure that there really is no concurrent page table access. Hitting this bug causes a lockdep warning in collapse_and_free_pmd(), in the line "lockdep_assert_held_write(&vma->anon_vma->root->rwsem)". It can also lead to use-after-free access.

osv:DEBIAN-CVE-2023-52935

linux

Fixed versions: 6.1.11-1

linux

Fixed versions: 6.1.11-1

linux

Fixed versions: 6.1.11-1

Complete source record
{
  "id": "558dc62903866c42c50075cc3d48b6920c1f1be5425b08096a1c26e095f0c690",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2023-52935",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2023-52935",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: fix ->anon_vma race If an ->anon_vma is attached to the VMA, collapse_and_free_pmd() requires it to be locked. Page table traversal is allowed under any one of the mmap lock, the anon_vma lock (if the VMA is associated with an anon_vma), and the mapping lock (if the VMA is associated with a mapping); and so to be able to remove page tables, we must hold all three of them. retract_page_tables() bails out if an ->anon_vma is attached, but does this check before holding the mmap lock (as the comment above the check explains). If we racily merged an existing ->anon_vma (shared with a child process) from a neighboring VMA, subsequent rmap traversals on pages belonging to the child will be able to see the page tables that we are concurrently removing while assuming that nothing else can access them. Repeat the ->anon_vma check once we hold the mmap lock to ensure that there really is no concurrent page table access. Hitting this bug causes a lockdep warning in collapse_and_free_pmd(), in the line \"lockdep_assert_held_write(&vma->anon_vma->root->rwsem)\". It can also lead to use-after-free access.",
    "evidence": "osv:DEBIAN-CVE-2023-52935",
    "products": [
      {
        "name": {
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          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
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            "evidence": "/affected/0/ranges"
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        "affected_versions": []
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      {
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    "severity": "high",
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      "aliases": [
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      ],
      "metrics": [
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          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
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            {
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          ],
          "package": {
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            "purl": "pkg:deb/debian/linux?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52935.json"
          },
          "ecosystem_specific": {
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          "package": {
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            "purl": "pkg:deb/debian/linux?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-52935.json"
          },
          "ecosystem_specific": {
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        {
          "ranges": [
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              ]
            }
          ],
          "package": {
            "name": "linux",
            "purl": "pkg:deb/debian/linux?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
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          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
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        }
      ],
      "modified": "2026-10-26T18:02:43.854673605Z",
      "provider": "osv",
      "upstream": [
        "CVE-2023-52935"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2023-52935"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2023-52935",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 456726,
  "published_at": "2025-03-27T17:15:43.33+00:00"
}