Vulnerability-Lookup

GHSA-6FH9-96WW-PVWQ

Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-11 09:30

Details

In the Linux kernel, the following vulnerability has been resolved:

mm/page_alloc: clear page->private in free_pages_prepare()

Several subsystems (slub, shmem, ttm, etc.) use page->private but don't clear it before freeing pages. When these pages are later allocated as high-order pages and split via split_page(), tail pages retain stale page->private values.

This causes a use-after-free in the swap subsystem. The swap code uses page->private to track swap count continuations, assuming freshly allocated pages have page->private == 0. When stale values are present, swap_count_continued() incorrectly assumes the continuation list is valid and iterates over uninitialized page->lru containing LIST_POISON values, causing a crash:

KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107] RIP: 0010:__do_sys_swapoff+0x1151/0x1860

Fix this by clearing page->private in free_pages_prepare(), ensuring all freed pages have clean state regardless of previous use.

Severity ?

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-43303"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-08T14:16:37Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_alloc: clear page-\u003eprivate in free_pages_prepare()\n\nSeveral subsystems (slub, shmem, ttm, etc.) use page-\u003eprivate but don\u0027t\nclear it before freeing pages.  When these pages are later allocated as\nhigh-order pages and split via split_page(), tail pages retain stale\npage-\u003eprivate values.\n\nThis causes a use-after-free in the swap subsystem.  The swap code uses\npage-\u003eprivate to track swap count continuations, assuming freshly\nallocated pages have page-\u003eprivate == 0.  When stale values are present,\nswap_count_continued() incorrectly assumes the continuation list is valid\nand iterates over uninitialized page-\u003elru containing LIST_POISON values,\ncausing a crash:\n\n  KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]\n  RIP: 0010:__do_sys_swapoff+0x1151/0x1860\n\nFix this by clearing page-\u003eprivate in free_pages_prepare(), ensuring all\nfreed pages have clean state regardless of previous use.",
  "id": "GHSA-6fh9-96ww-pvwq",
  "modified": "2026-05-11T09:30:29Z",
  "published": "2026-05-08T15:31:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43303"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/23b82b7a26182ad840ae67d390d7ec9771e8c00f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ac1ea219590c09572ed5992dc233bbf7bb70fef9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d757c793853ec5483eb41ec2942c300b8fa720fb"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-43303 (GCVE-0-2026-43303)

Vulnerability from cvelistv5 – Published: 2026-05-08 13:11 – Updated: 2026-05-11 22:21

Title

mm/page_alloc: clear page->private in free_pages_prepare()

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/page_alloc: clear page->private in free_pages_prepare() Several subsystems (slub, shmem, ttm, etc.) use page->private but don't clear it before freeing pages. When these pages are later allocated as high-order pages and split via split_page(), tail pages retain stale page->private values. This causes a use-after-free in the swap subsystem. The swap code uses page->private to track swap count continuations, assuming freshly allocated pages have page->private == 0. When stale values are present, swap_count_continued() incorrectly assumes the continuation list is valid and iterates over uninitialized page->lru containing LIST_POISON values, causing a crash: KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107] RIP: 0010:__do_sys_swapoff+0x1151/0x1860 Fix this by clearing page->private in free_pages_prepare(), ensuring all freed pages have clean state regardless of previous use.

Severity ?

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/23b82b7a26182ad84…
https://git.kernel.org/stable/c/d757c793853ec5483…
https://git.kernel.org/stable/c/ac1ea219590c09572…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3b8000ae185cb068adbda5f966a3835053c85fd4 , < 23b82b7a26182ad840ae67d390d7ec9771e8c00f (git) Affected: 3b8000ae185cb068adbda5f966a3835053c85fd4 , < d757c793853ec5483eb41ec2942c300b8fa720fb (git) Affected: 3b8000ae185cb068adbda5f966a3835053c85fd4 , < ac1ea219590c09572ed5992dc233bbf7bb70fef9 (git)
Linux	Linux	Affected: 5.18 Unaffected: 0 , < 5.18 (semver) Unaffected: 6.18.16 , ≤ 6.18.* (semver) Unaffected: 6.19.6 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "mm/page_alloc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "23b82b7a26182ad840ae67d390d7ec9771e8c00f",
              "status": "affected",
              "version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
              "versionType": "git"
            },
            {
              "lessThan": "d757c793853ec5483eb41ec2942c300b8fa720fb",
              "status": "affected",
              "version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
              "versionType": "git"
            },
            {
              "lessThan": "ac1ea219590c09572ed5992dc233bbf7bb70fef9",
              "status": "affected",
              "version": "3b8000ae185cb068adbda5f966a3835053c85fd4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "mm/page_alloc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "lessThan": "5.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.16",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.16",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.6",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "5.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_alloc: clear page-\u003eprivate in free_pages_prepare()\n\nSeveral subsystems (slub, shmem, ttm, etc.) use page-\u003eprivate but don\u0027t\nclear it before freeing pages.  When these pages are later allocated as\nhigh-order pages and split via split_page(), tail pages retain stale\npage-\u003eprivate values.\n\nThis causes a use-after-free in the swap subsystem.  The swap code uses\npage-\u003eprivate to track swap count continuations, assuming freshly\nallocated pages have page-\u003eprivate == 0.  When stale values are present,\nswap_count_continued() incorrectly assumes the continuation list is valid\nand iterates over uninitialized page-\u003elru containing LIST_POISON values,\ncausing a crash:\n\n  KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]\n  RIP: 0010:__do_sys_swapoff+0x1151/0x1860\n\nFix this by clearing page-\u003eprivate in free_pages_prepare(), ensuring all\nfreed pages have clean state regardless of previous use."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T22:21:56.846Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/23b82b7a26182ad840ae67d390d7ec9771e8c00f"
        },
        {
          "url": "https://git.kernel.org/stable/c/d757c793853ec5483eb41ec2942c300b8fa720fb"
        },
        {
          "url": "https://git.kernel.org/stable/c/ac1ea219590c09572ed5992dc233bbf7bb70fef9"
        }
      ],
      "title": "mm/page_alloc: clear page-\u003eprivate in free_pages_prepare()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43303",
    "datePublished": "2026-05-08T13:11:23.561Z",
    "dateReserved": "2026-05-01T14:12:56.000Z",
    "dateUpdated": "2026-05-11T22:21:56.846Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-6FH9-96WW-PVWQ

CVE-2026-43303 (GCVE-0-2026-43303)

Tags

Sightings

Nomenclature