{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "e65920661708b7c0f3db45c9cd5d0095034ee37f"
            },
            {
              "fixed": "a6573f3ffc19542de9ebc1a2b1f930fd48ba538c"
            },
            {
              "fixed": "aefcec3bebdeed2bff444378122300763325ba23"
            },
            {
              "fixed": "8f3b99c50dd0da1777994ce7c7e60d39b9f60f4b"
            },
            {
              "fixed": "5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.12.0"
            },
            {
              "fixed": "6.12.110"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.51"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89835.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: avoid NULL checkpoint thread access in sysfs\n\ncheckpoint_merge can be enabled even when no checkpoint merge thread is\nrunning. A read-only mount is one case: f2fs does not start\nf2fs_issue_ckpt there, but ckpt_thread_ioprio is still writable through\nsysfs.\n\nThe ckpt_thread_ioprio store path updates the saved ioprio value and,\nwhen checkpoint_merge is enabled, calls set_task_ioprio() for the\ncheckpoint thread. If cprc-\u003ef2fs_issue_ckpt is NULL, that dereferences a\nNULL task pointer.\n\nProtect ckpt_thread_ioprio sysfs writes with s_umount as well, so the\ncheckpoint thread cannot disappear under the store path while updating\nits ioprio.",
  "id": "CVE-2026-89835",
  "modified": "2026-09-18T03:30:40.727762375Z",
  "published": "2026-09-16T10:31:08.636Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8f3b99c50dd0da1777994ce7c7e60d39b9f60f4b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a6573f3ffc19542de9ebc1a2b1f930fd48ba538c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aefcec3bebdeed2bff444378122300763325ba23"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89835.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89835"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "f2fs: avoid NULL checkpoint thread access in sysfs"
}