{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "df263d9a7dffee94ca5391120ee3b0587efa07f1"
            },
            {
              "fixed": "8ffedc6573a665cdc31ebe47eae7b32b78d0df83"
            },
            {
              "fixed": "34a00895d032a414830d41106a09329ae6c251b6"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.6.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89755.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/migrate_device: clear stale mapping after freeing swapcache\n\n__migrate_device_pages() reads the folio mapping before calling\nfolio_free_swap().  When folio_free_swap() succeeds, the folio is removed\nfrom the swap cache, but the saved mapping still points to swap_space.\n\nPassing the stale mapping to folio_migrate_mapping() makes it use the\nmapped-folio path for a folio that is no longer in swapcache.  It can then\noperate on swap_space.i_pages with invalid reference accounting,\neventually triggering a folio reference count BUG.\n\nAfter a successful split, nr still contains the number of pages in the\noriginal large folio, although each resulting page is now a separate\norder-0 folio.  Reset nr to 1 so each split folio is processed separately,\nincluding its own swapcache removal and mapping lookup.\n\nRefresh the saved mapping after folio_free_swap() so the current folio\nstate is used during migration.",
  "id": "CVE-2026-89755",
  "modified": "2026-09-15T03:30:48.329365375Z",
  "published": "2026-09-11T19:46:58.295Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/34a00895d032a414830d41106a09329ae6c251b6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8ffedc6573a665cdc31ebe47eae7b32b78d0df83"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89755.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89755"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "mm/migrate_device: clear stale mapping after freeing swapcache"
}