Vulnerability-Lookup

GHSA-PHH3-RPF3-3Q9P

Vulnerability from github – Published: 2025-01-21 15:31 – Updated: 2025-01-23 00:33

Details

In the Linux kernel, the following vulnerability has been resolved:

btrfs: avoid NULL pointer dereference if no valid extent tree

[BUG] Syzbot reported a crash with the following call trace:

BTRFS info (device loop0): scrub: started on devid 1 BUG: kernel NULL pointer dereference, address: 0000000000000208 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 106e70067 P4D 106e70067 PUD 107143067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 UID: 0 PID: 689 Comm: repro Kdump: loaded Tainted: G O 6.13.0-rc4-custom+ #206 Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:find_first_extent_item+0x26/0x1f0 [btrfs] Call Trace: scrub_find_fill_first_stripe+0x13d/0x3b0 [btrfs] scrub_simple_mirror+0x175/0x260 [btrfs] scrub_stripe+0x5d4/0x6c0 [btrfs] scrub_chunk+0xbb/0x170 [btrfs] scrub_enumerate_chunks+0x2f4/0x5f0 [btrfs] btrfs_scrub_dev+0x240/0x600 [btrfs] btrfs_ioctl+0x1dc8/0x2fa0 [btrfs] ? do_sys_openat2+0xa5/0xf0 __x64_sys_ioctl+0x97/0xc0 do_syscall_64+0x4f/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e

[CAUSE] The reproducer is using a corrupted image where extent tree root is corrupted, thus forcing to use "rescue=all,ro" mount option to mount the image.

Then it triggered a scrub, but since scrub relies on extent tree to find where the data/metadata extents are, scrub_find_fill_first_stripe() relies on an non-empty extent root.

But unfortunately scrub_find_fill_first_stripe() doesn't really expect an NULL pointer for extent root, it use extent_root to grab fs_info and triggered a NULL pointer dereference.

[FIX] Add an extra check for a valid extent root at the beginning of scrub_find_fill_first_stripe().

The new error path is introduced by 42437a6386ff ("btrfs: introduce mount option rescue=ignorebadroots"), but that's pretty old, and later commit b979547513ff ("btrfs: scrub: introduce helper to find and fill sector info for a scrub_stripe") changed how we do scrub.

So for kernels older than 6.6, the fix will need manual backport.

Severity

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2025-21658"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-01-21T13:15:09Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: avoid NULL pointer dereference if no valid extent tree\n\n[BUG]\nSyzbot reported a crash with the following call trace:\n\n  BTRFS info (device loop0): scrub: started on devid 1\n  BUG: kernel NULL pointer dereference, address: 0000000000000208\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD 106e70067 P4D 106e70067 PUD 107143067 PMD 0\n  Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI\n  CPU: 1 UID: 0 PID: 689 Comm: repro Kdump: loaded Tainted: G           O       6.13.0-rc4-custom+ #206\n  Tainted: [O]=OOT_MODULE\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022\n  RIP: 0010:find_first_extent_item+0x26/0x1f0 [btrfs]\n  Call Trace:\n   \u003cTASK\u003e\n   scrub_find_fill_first_stripe+0x13d/0x3b0 [btrfs]\n   scrub_simple_mirror+0x175/0x260 [btrfs]\n   scrub_stripe+0x5d4/0x6c0 [btrfs]\n   scrub_chunk+0xbb/0x170 [btrfs]\n   scrub_enumerate_chunks+0x2f4/0x5f0 [btrfs]\n   btrfs_scrub_dev+0x240/0x600 [btrfs]\n   btrfs_ioctl+0x1dc8/0x2fa0 [btrfs]\n   ? do_sys_openat2+0xa5/0xf0\n   __x64_sys_ioctl+0x97/0xc0\n   do_syscall_64+0x4f/0x120\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\n   \u003c/TASK\u003e\n\n[CAUSE]\nThe reproducer is using a corrupted image where extent tree root is\ncorrupted, thus forcing to use \"rescue=all,ro\" mount option to mount the\nimage.\n\nThen it triggered a scrub, but since scrub relies on extent tree to find\nwhere the data/metadata extents are, scrub_find_fill_first_stripe()\nrelies on an non-empty extent root.\n\nBut unfortunately scrub_find_fill_first_stripe() doesn\u0027t really expect\nan NULL pointer for extent root, it use extent_root to grab fs_info and\ntriggered a NULL pointer dereference.\n\n[FIX]\nAdd an extra check for a valid extent root at the beginning of\nscrub_find_fill_first_stripe().\n\nThe new error path is introduced by 42437a6386ff (\"btrfs: introduce\nmount option rescue=ignorebadroots\"), but that\u0027s pretty old, and later\ncommit b979547513ff (\"btrfs: scrub: introduce helper to find and fill\nsector info for a scrub_stripe\") changed how we do scrub.\n\nSo for kernels older than 6.6, the fix will need manual backport.",
  "id": "GHSA-phh3-rpf3-3q9p",
  "modified": "2025-01-23T00:33:59Z",
  "published": "2025-01-21T15:31:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-21658"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/24b85a8b0310e0144da9ab30be42e87e6476638a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6aecd91a5c5b68939cf4169e32bc49f3cd2dd329"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aee5f69f3e6cd82bfefaca1b70b40b6cd8f3f784"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2025-21658 (GCVE-0-2025-21658)

Vulnerability from cvelistv5 – Published: 2025-01-21 12:18 – Updated: 2026-05-11 21:03

Title

btrfs: avoid NULL pointer dereference if no valid extent tree

Summary

In the Linux kernel, the following vulnerability has been resolved: btrfs: avoid NULL pointer dereference if no valid extent tree [BUG] Syzbot reported a crash with the following call trace: BTRFS info (device loop0): scrub: started on devid 1 BUG: kernel NULL pointer dereference, address: 0000000000000208 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 106e70067 P4D 106e70067 PUD 107143067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 UID: 0 PID: 689 Comm: repro Kdump: loaded Tainted: G O 6.13.0-rc4-custom+ #206 Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:find_first_extent_item+0x26/0x1f0 [btrfs] Call Trace: <TASK> scrub_find_fill_first_stripe+0x13d/0x3b0 [btrfs] scrub_simple_mirror+0x175/0x260 [btrfs] scrub_stripe+0x5d4/0x6c0 [btrfs] scrub_chunk+0xbb/0x170 [btrfs] scrub_enumerate_chunks+0x2f4/0x5f0 [btrfs] btrfs_scrub_dev+0x240/0x600 [btrfs] btrfs_ioctl+0x1dc8/0x2fa0 [btrfs] ? do_sys_openat2+0xa5/0xf0 __x64_sys_ioctl+0x97/0xc0 do_syscall_64+0x4f/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> [CAUSE] The reproducer is using a corrupted image where extent tree root is corrupted, thus forcing to use "rescue=all,ro" mount option to mount the image. Then it triggered a scrub, but since scrub relies on extent tree to find where the data/metadata extents are, scrub_find_fill_first_stripe() relies on an non-empty extent root. But unfortunately scrub_find_fill_first_stripe() doesn't really expect an NULL pointer for extent root, it use extent_root to grab fs_info and triggered a NULL pointer dereference. [FIX] Add an extra check for a valid extent root at the beginning of scrub_find_fill_first_stripe(). The new error path is introduced by 42437a6386ff ("btrfs: introduce mount option rescue=ignorebadroots"), but that's pretty old, and later commit b979547513ff ("btrfs: scrub: introduce helper to find and fill sector info for a scrub_stripe") changed how we do scrub. So for kernels older than 6.6, the fix will need manual backport.

Severity

5.5 (Medium)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-10-01 19:52 UTC

CWE

CWE-476 - NULL Pointer Dereference

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/24b85a8b0310e0144…
https://git.kernel.org/stable/c/aee5f69f3e6cd82bf…
https://git.kernel.org/stable/c/6aecd91a5c5b68939…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 42437a6386ffeaaf200731e73d723ea491f3fe7d , < 24b85a8b0310e0144da9ab30be42e87e6476638a (git) Affected: 42437a6386ffeaaf200731e73d723ea491f3fe7d , < aee5f69f3e6cd82bfefaca1b70b40b6cd8f3f784 (git) Affected: 42437a6386ffeaaf200731e73d723ea491f3fe7d , < 6aecd91a5c5b68939cf4169e32bc49f3cd2dd329 (git)
Linux	Linux	Affected: 5.11 Unaffected: 0 , < 5.11 (semver) Unaffected: 6.6.72 , ≤ 6.6.* (semver) Unaffected: 6.12.10 , ≤ 6.12.* (semver) Unaffected: 6.13 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 5.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2025-21658",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-10-01T19:52:37.080379Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-476",
                "description": "CWE-476 NULL Pointer Dereference",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-10-01T19:57:13.496Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/scrub.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "24b85a8b0310e0144da9ab30be42e87e6476638a",
              "status": "affected",
              "version": "42437a6386ffeaaf200731e73d723ea491f3fe7d",
              "versionType": "git"
            },
            {
              "lessThan": "aee5f69f3e6cd82bfefaca1b70b40b6cd8f3f784",
              "status": "affected",
              "version": "42437a6386ffeaaf200731e73d723ea491f3fe7d",
              "versionType": "git"
            },
            {
              "lessThan": "6aecd91a5c5b68939cf4169e32bc49f3cd2dd329",
              "status": "affected",
              "version": "42437a6386ffeaaf200731e73d723ea491f3fe7d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/scrub.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.11"
            },
            {
              "lessThan": "5.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.72",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.72",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.10",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: avoid NULL pointer dereference if no valid extent tree\n\n[BUG]\nSyzbot reported a crash with the following call trace:\n\n  BTRFS info (device loop0): scrub: started on devid 1\n  BUG: kernel NULL pointer dereference, address: 0000000000000208\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD 106e70067 P4D 106e70067 PUD 107143067 PMD 0\n  Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI\n  CPU: 1 UID: 0 PID: 689 Comm: repro Kdump: loaded Tainted: G           O       6.13.0-rc4-custom+ #206\n  Tainted: [O]=OOT_MODULE\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022\n  RIP: 0010:find_first_extent_item+0x26/0x1f0 [btrfs]\n  Call Trace:\n   \u003cTASK\u003e\n   scrub_find_fill_first_stripe+0x13d/0x3b0 [btrfs]\n   scrub_simple_mirror+0x175/0x260 [btrfs]\n   scrub_stripe+0x5d4/0x6c0 [btrfs]\n   scrub_chunk+0xbb/0x170 [btrfs]\n   scrub_enumerate_chunks+0x2f4/0x5f0 [btrfs]\n   btrfs_scrub_dev+0x240/0x600 [btrfs]\n   btrfs_ioctl+0x1dc8/0x2fa0 [btrfs]\n   ? do_sys_openat2+0xa5/0xf0\n   __x64_sys_ioctl+0x97/0xc0\n   do_syscall_64+0x4f/0x120\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\n   \u003c/TASK\u003e\n\n[CAUSE]\nThe reproducer is using a corrupted image where extent tree root is\ncorrupted, thus forcing to use \"rescue=all,ro\" mount option to mount the\nimage.\n\nThen it triggered a scrub, but since scrub relies on extent tree to find\nwhere the data/metadata extents are, scrub_find_fill_first_stripe()\nrelies on an non-empty extent root.\n\nBut unfortunately scrub_find_fill_first_stripe() doesn\u0027t really expect\nan NULL pointer for extent root, it use extent_root to grab fs_info and\ntriggered a NULL pointer dereference.\n\n[FIX]\nAdd an extra check for a valid extent root at the beginning of\nscrub_find_fill_first_stripe().\n\nThe new error path is introduced by 42437a6386ff (\"btrfs: introduce\nmount option rescue=ignorebadroots\"), but that\u0027s pretty old, and later\ncommit b979547513ff (\"btrfs: scrub: introduce helper to find and fill\nsector info for a scrub_stripe\") changed how we do scrub.\n\nSo for kernels older than 6.6, the fix will need manual backport."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T21:03:56.225Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/24b85a8b0310e0144da9ab30be42e87e6476638a"
        },
        {
          "url": "https://git.kernel.org/stable/c/aee5f69f3e6cd82bfefaca1b70b40b6cd8f3f784"
        },
        {
          "url": "https://git.kernel.org/stable/c/6aecd91a5c5b68939cf4169e32bc49f3cd2dd329"
        }
      ],
      "title": "btrfs: avoid NULL pointer dereference if no valid extent tree",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-21658",
    "datePublished": "2025-01-21T12:18:14.578Z",
    "dateReserved": "2024-12-29T08:45:45.731Z",
    "dateUpdated": "2026-05-11T21:03:56.225Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-PHH3-RPF3-3Q9P

CVE-2025-21658 (GCVE-0-2025-21658)

Tags

Sightings

Nomenclature

Related by attack behaviour