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CVE-2025-40025 (GCVE-0-2025-40025)

Vulnerability from cvelistv5 – Published: 2025-10-28 09:32 – Updated: 2026-08-05 12:07
VLAI
Title
f2fs: fix to do sanity check on node footer for non inode dnode
Summary
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on node footer for non inode dnode As syzbot reported below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/file.c:1243! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full) RIP: 0010:f2fs_truncate_hole+0x69e/0x6c0 fs/f2fs/file.c:1243 Call Trace: <TASK> f2fs_punch_hole+0x2db/0x330 fs/f2fs/file.c:1306 f2fs_fallocate+0x546/0x990 fs/f2fs/file.c:2018 vfs_fallocate+0x666/0x7e0 fs/open.c:342 ksys_fallocate fs/open.c:366 [inline] __do_sys_fallocate fs/open.c:371 [inline] __se_sys_fallocate fs/open.c:369 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:369 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1e65f8ebe9 w/ a fuzzed image, f2fs may encounter panic due to it detects inconsistent truncation range in direct node in f2fs_truncate_hole(). The root cause is: a non-inode dnode may has the same footer.ino and footer.nid, so the dnode will be parsed as an inode, then ADDRS_PER_PAGE() may return wrong blkaddr count which may be 923 typically, by chance, dn.ofs_in_node is equal to 923, then count can be calculated to 0 in below statement, later it will trigger panic w/ f2fs_bug_on(, count == 0 || ...). count = min(end_offset - dn.ofs_in_node, pg_end - pg_start); This patch introduces a new node_type NODE_TYPE_NON_INODE, then allowing passing the new_type to sanity_check_node_footer in f2fs_get_node_folio() to detect corruption that a non-inode dnode has the same footer.ino and footer.nid. Scripts to reproduce: mkfs.f2fs -f /dev/vdb mount /dev/vdb /mnt/f2fs touch /mnt/f2fs/foo touch /mnt/f2fs/bar dd if=/dev/zero of=/mnt/f2fs/foo bs=1M count=8 umount /mnt/f2fs inject.f2fs --node --mb i_nid --nid 4 --idx 0 --val 5 /dev/vdb mount /dev/vdb /mnt/f2fs xfs_io /mnt/f2fs/foo -c "fpunch 6984k 4k"
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 , < 186098f34b8a5d65eb828f952c8cc56272c60ea0 (git)
Affected: 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 , < c18ecd99e0c707ef8f83cace861cbc3162f4fdf1 (git)
guessed Create a notification for this product.
Linux Linux Affected: 3.8
Unaffected: 0 , < 3.8 (semver)
Unaffected: 6.17.2 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/f2fs.h",
            "fs/f2fs/gc.c",
            "fs/f2fs/node.c",
            "fs/f2fs/node.h",
            "fs/f2fs/recovery.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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            "fs/f2fs/node.c",
            "fs/f2fs/node.h",
            "fs/f2fs/recovery.c"
          ],
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          "vendor": "Linux",
          "versions": [
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              "version": "3.8"
            },
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              "status": "unaffected",
              "version": "0",
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              "status": "unaffected",
              "version": "6.17.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
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        }
      ],
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17.2",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
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                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                }
              ],
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              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to do sanity check on node footer for non inode dnode\n\nAs syzbot reported below:\n\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/file.c:1243!\nOops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\nCPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full)\nRIP: 0010:f2fs_truncate_hole+0x69e/0x6c0 fs/f2fs/file.c:1243\nCall Trace:\n \u003cTASK\u003e\n f2fs_punch_hole+0x2db/0x330 fs/f2fs/file.c:1306\n f2fs_fallocate+0x546/0x990 fs/f2fs/file.c:2018\n vfs_fallocate+0x666/0x7e0 fs/open.c:342\n ksys_fallocate fs/open.c:366 [inline]\n __do_sys_fallocate fs/open.c:371 [inline]\n __se_sys_fallocate fs/open.c:369 [inline]\n __x64_sys_fallocate+0xc0/0x110 fs/open.c:369\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f1e65f8ebe9\n\nw/ a fuzzed image, f2fs may encounter panic due to it detects inconsistent\ntruncation range in direct node in f2fs_truncate_hole().\n\nThe root cause is: a non-inode dnode may has the same footer.ino and\nfooter.nid, so the dnode will be parsed as an inode, then ADDRS_PER_PAGE()\nmay return wrong blkaddr count which may be 923 typically, by chance,\ndn.ofs_in_node is equal to 923, then count can be calculated to 0 in below\nstatement, later it will trigger panic w/ f2fs_bug_on(, count == 0 || ...).\n\n\tcount = min(end_offset - dn.ofs_in_node, pg_end - pg_start);\n\nThis patch introduces a new node_type NODE_TYPE_NON_INODE, then allowing\npassing the new_type to sanity_check_node_footer in f2fs_get_node_folio()\nto detect corruption that a non-inode dnode has the same footer.ino and\nfooter.nid.\n\nScripts to reproduce:\nmkfs.f2fs -f /dev/vdb\nmount /dev/vdb /mnt/f2fs\ntouch /mnt/f2fs/foo\ntouch /mnt/f2fs/bar\ndd if=/dev/zero of=/mnt/f2fs/foo bs=1M count=8\numount /mnt/f2fs\ninject.f2fs --node --mb i_nid --nid 4 --idx 0 --val 5 /dev/vdb\nmount /dev/vdb /mnt/f2fs\nxfs_io /mnt/f2fs/foo -c \"fpunch 6984k 4k\""
        }
      ],
      "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 vulnerability is reached through local syscalls (fallocate/read/write/truncate) on a file residing in a mounted, attacker-crafted f2fs image; no network or remote protocol handling is involved.\nAC:L - The attacker fully controls the on-disk node footer (footer.ino == footer.nid) and the punch-hole offset/length, so the misparse and the resulting out-of-bounds access are deterministic \u2014 the commit ships a byte-exact reproducer via inject.f2fs plus a single xfs_io fpunch.\nPR:L - Once the crafted image is mounted (removable media/automount, shared workstation, or Android SD card), triggering requires only an unprivileged local user issuing a normal fallocate or read on a file in that filesystem \u2014 no capability check exists on the path from vfs_fallocate to f2fs_get_dnode_of_data.\nUI:N - After the malicious image is present, the attacker performs every step themselves; no victim action is needed to reach f2fs_truncate_hole or the read/write paths that hit the same misparse.\nS:U - The corruption is confined to kernel memory within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - f2fs_data_blkaddr() indexes i_addr (base byte 360) with a direct-node offset up to 1017, reading past the end of the 4 KiB node folio; the leaked adjacent kernel memory becomes dn-\u003edata_blkaddr, which f2fs then treats as a physical block address and may read into the page cache, exposing arbitrary disk and heap contents.\nI:H - __set_data_blkaddr() writes through the same out-of-bounds pointer, and with CONFIG_F2FS_CHECK_FS disabled the f2fs_bug_on degrades to WARN_ON so the underflowed, attacker-chosen count is passed to f2fs_truncate_data_blocks_range, yielding an attacker-controlled-length out-of-bounds write past the node folio plus invalidation of arbitrary filesystem blocks.\nA:H - With CONFIG_F2FS_CHECK_FS enabled this is a hard BUG_ON at fs/f2fs/file.c:1243 causing immediate kernel panic (as syzbot reported), and without it the out-of-bounds writes corrupt adjacent kernel memory and filesystem metadata, crashing the system."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:07:07.729Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/186098f34b8a5d65eb828f952c8cc56272c60ea0"
        },
        {
          "url": "https://git.kernel.org/stable/c/c18ecd99e0c707ef8f83cace861cbc3162f4fdf1"
        }
      ],
      "title": "f2fs: fix to do sanity check on node footer for non inode dnode",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40025",
    "datePublished": "2025-10-28T09:32:31.806Z",
    "dateReserved": "2025-04-16T07:20:57.152Z",
    "dateUpdated": "2026-08-05T12:07:07.729Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-40025",
      "date": "2026-09-18",
      "epss": "0.00133",
      "percentile": "0.03229"
    },
    "microsoft_vex": {
      "current_release_date": "2025-10-29T01:02:43.000Z",
      "cve": "CVE-2025-40025",
      "id": "msrc_CVE-2025-40025",
      "initial_release_date": "2025-10-02T00:00:00.000Z",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "f2fs: fix to do sanity check on node footer for non inode dnode",
      "url": "https://msrc.microsoft.com/csaf/vex/2025/msrc_cve-2025-40025.json",
      "version": "1"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
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                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "fs/f2fs/f2fs.h",
                  "fs/f2fs/gc.c",
                  "fs/f2fs/node.c",
                  "fs/f2fs/node.h",
                  "fs/f2fs/recovery.c"
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                "product": "Linux",
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                  "fs/f2fs/node.h",
                  "fs/f2fs/recovery.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "3.8"
                  },
                  {
                    "lessThan": "3.8",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
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                    "status": "unaffected",
                    "version": "6.17.2",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "6.18",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to do sanity check on node footer for non inode dnode\n\nAs syzbot reported below:\n\n------------[ cut here ]------------\nkernel BUG at fs/f2fs/file.c:1243!\nOops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\nCPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full)\nRIP: 0010:f2fs_truncate_hole+0x69e/0x6c0 fs/f2fs/file.c:1243\nCall Trace:\n \u003cTASK\u003e\n f2fs_punch_hole+0x2db/0x330 fs/f2fs/file.c:1306\n f2fs_fallocate+0x546/0x990 fs/f2fs/file.c:2018\n vfs_fallocate+0x666/0x7e0 fs/open.c:342\n ksys_fallocate fs/open.c:366 [inline]\n __do_sys_fallocate fs/open.c:371 [inline]\n __se_sys_fallocate fs/open.c:369 [inline]\n __x64_sys_fallocate+0xc0/0x110 fs/open.c:369\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f1e65f8ebe9\n\nw/ a fuzzed image, f2fs may encounter panic due to it detects inconsistent\ntruncation range in direct node in f2fs_truncate_hole().\n\nThe root cause is: a non-inode dnode may has the same footer.ino and\nfooter.nid, so the dnode will be parsed as an inode, then ADDRS_PER_PAGE()\nmay return wrong blkaddr count which may be 923 typically, by chance,\ndn.ofs_in_node is equal to 923, then count can be calculated to 0 in below\nstatement, later it will trigger panic w/ f2fs_bug_on(, count == 0 || ...).\n\n\tcount = min(end_offset - dn.ofs_in_node, pg_end - pg_start);\n\nThis patch introduces a new node_type NODE_TYPE_NON_INODE, then allowing\npassing the new_type to sanity_check_node_footer in f2fs_get_node_folio()\nto detect corruption that a non-inode dnode has the same footer.ino and\nfooter.nid.\n\nScripts to reproduce:\nmkfs.f2fs -f /dev/vdb\nmount /dev/vdb /mnt/f2fs\ntouch /mnt/f2fs/foo\ntouch /mnt/f2fs/bar\ndd if=/dev/zero of=/mnt/f2fs/foo bs=1M count=8\numount /mnt/f2fs\ninject.f2fs --node --mb i_nid --nid 4 --idx 0 --val 5 /dev/vdb\nmount /dev/vdb /mnt/f2fs\nxfs_io /mnt/f2fs/foo -c \"fpunch 6984k 4k\""
          }
        ],
        "id": "CVE-2025-40025",
        "lastModified": "2026-07-30T06:24:06.493",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            }
          ]
        },
        "published": "2025-10-28T10:15:40.920",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/186098f34b8a5d65eb828f952c8cc56272c60ea0"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/c18ecd99e0c707ef8f83cace861cbc3162f4fdf1"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Deferred"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-30T10:13:24+00:00",
      "cve": "CVE-2025-40025",
      "id": "CVE-2025-40025",
      "initial_release_date": "2025-10-28T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: f2fs: fix to do sanity check on node footer for non inode dnode",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-40025.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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