{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "efbcecdecefc26fa062c0e8210533ccad7d6bd4a"
            },
            {
              "fixed": "8b9b10fe5b8b492b27b9f4546742ea541a650213"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "fa724e235cfdb0fb0bb427d0f9dfe864ae27403e"
            },
            {
              "fixed": "81fc3868a7f726980ff845c1d0d271051e5f0f45"
            },
            {
              "fixed": "364b183230586a62660a7280c1eb20138338eeb5"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "6838bcac954487cc0a3c8a4ee1b3a3a30e244dc9"
            },
            {
              "last_affected": "75640976cf474eb41682a13f2dbe9534ac26ca50"
            },
            {
              "last_affected": "3513f3931c579ba2a715784c6dedc59e0d9282ee"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.18.44"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "6.12.105"
            },
            {
              "fixed": "6.13"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "7.1.8"
            },
            {
              "fixed": "7.2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "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-2026-89639.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC\n\ncifs_do_truncate() is invoked from cifs_open() without i_rwsem, so it\ncannot use cifs_resize_file_locked() to perform a proper fscache cookie\nresize.  Instead, add cifs_invalidate_cache() after cifs_setsize().\n\ncifs_invalidate_cache() calls fscache_invalidate(), which works without\nholding i_rwsem: it unconditionally increments inval_counter and sets\nFSCACHE_COOKIE_NO_DATA_TO_READ, ensuring that stale cached data is not\nserved once the cookie is later activated by fscache_use_cookie().\nTruncation to zero leaves no valid cached data, making invalidation the\ncorrect semantic here.",
  "id": "CVE-2026-89639",
  "modified": "2026-09-15T03:31:09.249546113Z",
  "published": "2026-09-11T19:45:32.532Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/364b183230586a62660a7280c1eb20138338eeb5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/81fc3868a7f726980ff845c1d0d271051e5f0f45"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8b9b10fe5b8b492b27b9f4546742ea541a650213"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89639.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89639"
    },
    {
      "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:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "cifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC"
}