CVE-2026-46175 (GCVE-0-2026-46175)
Vulnerability from cvelistv5
Published
2026-05-28 09:36
Modified
2026-08-05 12:30
Severity ?
7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix fsck inconsistency caused by FGGC of node block During FGGC node block migration, fsck may incorrectly treat the migrated node block as fsync-written data. The reproduction scenario: root@vm:/mnt/f2fs# seq 1 2048 | xargs -n 1 ./test_sync // write inline inode and sync root@vm:/mnt/f2fs# rm -f 1 root@vm:/mnt/f2fs# sync root@vm:/mnt/f2fs# f2fs_io gc_range // move data block in sync mode and not write CP SPO, "fsck --dry-run" find inode has already checkpointed but still with DENT_BIT_SHIFT set The root cause is that GC does not clear the dentry mark and fsync mark during node block migration, leading fsck to misinterpret them as user-issued fsync writes. In BGGC mode, node block migration is handled by f2fs_sync_node_pages(), which guarantees the dentry and fsync marks are cleared before writing. This patch move the set/clear of the fsync|dentry marks into __write_node_folio to make the logic clearer, and ensures the fsync|dentry mark is cleared in FGGC.
References
Impacted products
Vendor Product Version
Linux Linux Version: da011cc0da8cf4a60ddf4d2ae8b42902a3d71e5f
Version: da011cc0da8cf4a60ddf4d2ae8b42902a3d71e5f
Version: da011cc0da8cf4a60ddf4d2ae8b42902a3d71e5f
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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": [
            {
              "lessThan": "8be551f538dc5b64183e27bd45a7a0795263f760",
              "status": "affected",
              "version": "da011cc0da8cf4a60ddf4d2ae8b42902a3d71e5f",
              "versionType": "git"
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            {
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              "status": "affected",
              "version": "da011cc0da8cf4a60ddf4d2ae8b42902a3d71e5f",
              "versionType": "git"
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            {
              "lessThan": "c3e238bd1f56993f205ef83889d406dfeaf717a8",
              "status": "affected",
              "version": "da011cc0da8cf4a60ddf4d2ae8b42902a3d71e5f",
              "versionType": "git"
            }
          ]
        },
        {
          "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": "4.7"
            },
            {
              "lessThan": "4.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.30",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.30",
                  "versionStartIncluding": "4.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.7",
                  "versionStartIncluding": "4.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "4.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix fsck inconsistency caused by FGGC of node block\n\nDuring FGGC node block migration, fsck may incorrectly treat the\nmigrated node block as fsync-written data.\n\nThe reproduction scenario:\nroot@vm:/mnt/f2fs# seq 1 2048 | xargs -n 1 ./test_sync // write inline inode and sync\nroot@vm:/mnt/f2fs# rm -f 1\nroot@vm:/mnt/f2fs# sync\nroot@vm:/mnt/f2fs# f2fs_io gc_range // move data block in sync mode and not write CP\n  SPO, \"fsck --dry-run\" find inode has already checkpointed but still\n  with DENT_BIT_SHIFT set\n\nThe root cause is that GC does not clear the dentry mark and fsync mark\nduring node block migration, leading fsck to misinterpret them as\nuser-issued fsync writes.\n\nIn BGGC mode, node block migration is handled by f2fs_sync_node_pages(),\nwhich guarantees the dentry and fsync marks are cleared before writing.\n\nThis patch move the set/clear of the fsync|dentry marks into\n__write_node_folio to make the logic clearer, and ensures the\nfsync|dentry mark is cleared in FGGC."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - f2fs is a local block-device filesystem (default on Android/embedded); the vulnerable FGGC path is reached only by a local actor writing to a mounted f2fs volume, not over any network.\nAC:L - The attacker fully sets up the trigger (write+fsync an inline inode, delete it, exhaust free space to force FGGC of its node block); the corrupt on-disk state then persists until the next checkpoint, and routine power cycles/reboots on the target devices reliably invoke the faulty recovery.\nPR:L - While the GC ioctls require CAP_SYS_ADMIN, automatic foreground GC (f2fs_balance_fs \u2192 f2fs_gc promoting to FG_GC on low free space) runs the exact vulnerable path for any unprivileged user with write access to the filesystem.\nUI:N - Roll-forward recovery runs automatically during the next mount after a crash; no victim action is needed beyond the normal, automatic crash-and-remount cycle.\nS:U - The corruption is confined to the f2fs on-disk structures and the kernel managing them; it does not cross into a different security authority.\nC:N - The bug corrupts filesystem-consistency metadata but provides no read primitive over kernel memory or otherwise-inaccessible data, so there is no information disclosure.\nI:H - The migrated node block is misinterpreted as fsynced data, causing incorrect roll-forward recovery that resurrects deleted/stale inode metadata and leaves the on-disk filesystem inconsistent (fsck-detected) \u2014 a serious integrity compromise of stored data.\nA:H - A bad recovery can return an error, aborting the mount and rendering the filesystem/data unavailable until offline fsck (e.g. /data mount failure), and with CONFIG_F2FS_CHECK_FS the recovery error path hits BUG_ON(), crashing the kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:30:13.236Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/8be551f538dc5b64183e27bd45a7a0795263f760"
        },
        {
          "url": "https://git.kernel.org/stable/c/e7c6d30169b03307d27c4479563df79c08f3a746"
        },
        {
          "url": "https://git.kernel.org/stable/c/c3e238bd1f56993f205ef83889d406dfeaf717a8"
        }
      ],
      "title": "f2fs: fix fsck inconsistency caused by FGGC of node block",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-46175",
    "datePublished": "2026-05-28T09:36:29.522Z",
    "dateReserved": "2026-05-13T15:03:33.103Z",
    "dateUpdated": "2026-08-05T12:30:13.236Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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