CVE-2026-89829 (GCVE-0-2026-89829)
Vulnerability from cvelistv5
Published
2026-09-16 10:31
Modified
2026-10-19 08:53
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to pass folio->index to f2fs_sanity_check_node_footer() Otherwise in f2fs_sanity_check_node_footer(), it will check the same nid incorrectly.
References
Impacted products
Vendor Product Version
Linux Linux Version: cd2fec912a0f04390d446ed692f73f2da842855f
Version: 0a736109c9d29de0c26567e42cb99b27861aa8ba
Version: 0a736109c9d29de0c26567e42cb99b27861aa8ba
Version: 971aa8e2a4043d92bf62061b79f74fd4ac59165a
Version: 6.18.13   ≤
Version: 6.19.3   ≤
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/node.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "cd2fec912a0f04390d446ed692f73f2da842855f",
              "versionType": "git"
            },
            {
              "lessThan": "0b196c07407f48a41cd9741cf53e10cb1e23d2e5",
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              "versionType": "git"
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              "status": "affected",
              "version": "0a736109c9d29de0c26567e42cb99b27861aa8ba",
              "versionType": "git"
            },
            {
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              "version": "971aa8e2a4043d92bf62061b79f74fd4ac59165a",
              "versionType": "git"
            },
            {
              "lessThan": "6.18.51",
              "status": "affected",
              "version": "6.18.13",
              "versionType": "semver"
            },
            {
              "lessThan": "6.20",
              "status": "affected",
              "version": "6.19.3",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/node.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "lessThan": "7.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.51",
                  "versionStartIncluding": "6.18.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.5",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.19.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to pass folio-\u003eindex to f2fs_sanity_check_node_footer()\n\nOtherwise in f2fs_sanity_check_node_footer(), it will check the\nsame nid incorrectly."
        }
      ],
      "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"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The defect is in f2fs __write_node_folio() on the node-mapping writeback path, reached only from local VFS operations (fsync, write, checkpoint, GC, or reclaim) on a mounted f2fs volume; no network protocol (ksmbd/nfsd/packet) processes this node-footer check.\nAC:L - A crafted f2fs image fully controls the on-disk node footer nid. Related syzbot reports show that async node readahead of a fuzzed image followed by writeback deterministically hits the mismatched-nid case, with no race or layout the attacker cannot arrange.\nPR:L - Mounting f2fs requires privilege (no FS_USERNS_MOUNT), but once the volume is mounted\u2014Android userdata, automounted SD/USB, or a shared workstation\u2014any unprivileged local user can dirty node pages via write/fsync/fallocate/truncate and enter __write_node_folio with no capability check.\nUI:N - After the crafted image is mounted, the attacker triggers node writeback themselves through ordinary file syscalls or in-kernel checkpoint/reclaim; no separate victim action such as opening a file or confirming a prompt is required.\nS:U - The impact is kernel memory and f2fs metadata corruption on the host that mounted the volume; it does not cross a VM, IOMMU, or guest-to-host security boundary.\nC:H - __write_node_folio uses the attacker-controlled footer nid as the NAT key without a range check, so current_nat_addr() indexes nat_bitmap at an attacker-chosen offset (nid/NAT_ENTRY_PER_BLOCK), an unbounded out-of-bounds kernel read. The same nid confusion later parses the planted node with the wrong layout, leaking adjacent folio contents as in CVE-2025-40025.\nI:H - set_node_addr() and f2fs_do_write_node_page() commit the node folio under the footer nid, overwriting an arbitrary NAT entry and remapping any node. Subsequent operations on that nid write through the wrong inode-vs-dnode layout, producing out-of-bounds metadata writes past the node folio.\nA:H - A mismatched nid that fails f2fs_get_node_info() takes redirty_out, looping writepages indefinitely (the hang this check was added to stop). A nid that proceeds hits f2fs_bug_on() in set_node_addr()/write_end_io, panicking with CONFIG_F2FS_CHECK_FS or WARNing and corrupting the filesystem otherwise."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:53:22.927Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/a984446aa9d5b787afa3023fc7b44017b80fe3bc"
        },
        {
          "url": "https://git.kernel.org/stable/c/0b196c07407f48a41cd9741cf53e10cb1e23d2e5"
        },
        {
          "url": "https://git.kernel.org/stable/c/7e188e9f9437ab47c3237d609f1b26348d6fea1a"
        }
      ],
      "title": "f2fs: fix to pass folio-\u003eindex to f2fs_sanity_check_node_footer()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89829",
    "datePublished": "2026-09-16T10:31:01.761Z",
    "dateReserved": "2026-09-11T19:38:34.769Z",
    "dateUpdated": "2026-10-19T08:53:22.927Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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