{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2024-26960",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2024-26960",
    "idYear": 2024,
    "status": "PUBLISHED",
    "publishedAt": "2024-05-01T05:19:12.112Z",
    "updatedAt": "2026-10-15T00:39:36.857Z",
    "importedAt": "2026-10-24T01:57:07.518Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "mm: swap: fix race between free_swap_and_cache() and swapoff()",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: swap: fix race between free_swap_and_cache() and swapoff()\n\nThere was previously a theoretical window where swapoff() could run and\nteardown a swap_info_struct while a call to free_swap_and_cache() was\nrunning in another thread.  This could cause, amongst other bad\npossibilities, swap_page_trans_huge_swapped() (called by\nfree_swap_and_cache()) to access the freed memory for swap_map.\n\nThis is a theoretical problem and I haven't been able to provoke it from a\ntest case.  But there has been agreement based on code review that this is\npossible (see link below).\n\nFix it by using get_swap_device()/put_swap_device(), which will stall\nswapoff().  There was an extra check in _swap_info_get() to confirm that\nthe swap entry was not free.  This isn't present in get_swap_device()\nbecause it doesn't make sense in general due to the race between getting\nthe reference and swapoff.  So I've added an equivalent check directly in\nfree_swap_and_cache().\n\nDetails of how to provoke one possible issue (thanks to David Hildenbrand\nfor deriving this):\n\n--8<-----\n\n__swap_entry_free() might be the last user and result in\n\"count == SWAP_HAS_CACHE\".\n\nswapoff->try_to_unuse() will stop as soon as soon as si->inuse_pages==0.\n\nSo the question is: could someone reclaim the folio and turn\nsi->inuse_pages==0, before we completed swap_page_trans_huge_swapped().\n\nImagine the following: 2 MiB folio in the swapcache. Only 2 subpages are\nstill references by swap entries.\n\nProcess 1 still references subpage 0 via swap entry.\nProcess 2 still references subpage 1 via swap entry.\n\nProcess 1 quits. Calls free_swap_and_cache().\n-> count == SWAP_HAS_CACHE\n[then, preempted in the hypervisor etc.]\n\nProcess 2 quits. Calls free_swap_and_cache().\n-> count == SWAP_HAS_CACHE\n\nProcess 2 goes ahead, passes swap_page_trans_huge_swapped(), and calls\n__try_to_reclaim_swap().\n\n__try_to_reclaim_swap()->folio_free_swap()->delete_from_swap_cache()->\nput_swap_folio()->free_swap_slot()->swapcache_free_entries()->\nswap_entry_free()->swap_range_free()->\n...\nWRITE_ONCE(si->inuse_pages, si->inuse_pages - nr_entries);\n\nWhat stops swapoff to succeed after process 2 reclaimed the swap cache\nbut before process1 finished its call to swap_page_trans_huge_swapped()?\n\n--8<-----",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "7c00bafee87c7bac7ed9eced7c161f8e5332cb4e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d85c11c97ecf92d47a4b29e3faca714dc1f18d0d"
            },
            {
              "version": "7c00bafee87c7bac7ed9eced7c161f8e5332cb4e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "2da5568ee222ce0541bfe446a07998f92ed1643e"
            },
            {
              "version": "7c00bafee87c7bac7ed9eced7c161f8e5332cb4e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1ede7f1d7eed1738d1b9333fd1e152ccb450b86a"
            },
            {
              "version": "7c00bafee87c7bac7ed9eced7c161f8e5332cb4e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0f98f6d2fb5fad00f8299b84b85b6bc1b6d7d19a"
            },
            {
              "version": "7c00bafee87c7bac7ed9eced7c161f8e5332cb4e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3ce4c4c653e4e478ecb15d3c88e690f12cbf6b39"
            },
            {
              "version": "7c00bafee87c7bac7ed9eced7c161f8e5332cb4e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "363d17e7f7907c8e27a9e86968af0eaa2301787b"
            },
            {
              "version": "7c00bafee87c7bac7ed9eced7c161f8e5332cb4e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "82b1c07a0af603e3c47b906c8e991dc96f01688e"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.11",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.11"
            },
            {
              "version": "5.10.215",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.154",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.84",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.24",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.7.12",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.7.*"
            },
            {
              "version": "6.8.3",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.8.*"
            },
            {
              "version": "6.9",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}