Vulnerability-Lookup

FKIE_CVE-2026-68145

Vulnerability from fkie_nvd - Published: 2026-08-10 13:20 - Updated: 2026-08-17 05:18

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: iomap: fix out-of-bounds bitmap_set() with zero-length range ifs_set_range_dirty() and ifs_set_range_uptodate() compute last_blk as (off + len - 1) >> i_blkbits. When off is 0 and len is 0, the unsigned subtraction underflows to SIZE_MAX, producing a huge last_blk and nr_blks value that causes bitmap_set() to write far beyond the ifs->state allocation. Regarding ifs_set_range_uptodate(), it is temporarily safe because len cannot be passed in as 0. However, for ifs_set_range_dirty() this is reachable from __iomap_write_end(): when copy_folio_from_iter_atomic() returns 0 (e.g. user buffer fault) and the folio is already uptodate, the guard at the top of __iomap_write_end() does not trigger because !folio_test_uptodate() is false, and iomap_set_range_dirty() is called with copied == 0. Add a !len guard to both functions before the computation, so that a zero-length range is a no-op.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/7037e7bdcd26f46c080b8ce307dee5cb471c4b7c
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9c7d8f7c8994c790fca501dc45ce66e7356cbe05
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c5b6a48a8a716a7730e39af1cad083dc4ec955ce
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/fb4fad9105c88b1d82f1b3c39e3b6abea8249af6

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/iomap/buffered-io.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fb4fad9105c88b1d82f1b3c39e3b6abea8249af6",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            },
            {
              "lessThan": "7037e7bdcd26f46c080b8ce307dee5cb471c4b7c",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            },
            {
              "lessThan": "c5b6a48a8a716a7730e39af1cad083dc4ec955ce",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            },
            {
              "lessThan": "9c7d8f7c8994c790fca501dc45ce66e7356cbe05",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/iomap/buffered-io.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.6"
            },
            {
              "lessThan": "6.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\niomap: fix out-of-bounds bitmap_set() with zero-length range\n\nifs_set_range_dirty() and ifs_set_range_uptodate() compute last_blk\nas (off + len - 1) \u003e\u003e i_blkbits.  When off is 0 and len is 0, the\nunsigned subtraction underflows to SIZE_MAX, producing a huge\nlast_blk and nr_blks value that causes bitmap_set() to write far\nbeyond the ifs-\u003estate allocation.\n\nRegarding ifs_set_range_uptodate(), it is temporarily safe because len\ncannot be passed in as 0. However, for ifs_set_range_dirty() this is\nreachable from __iomap_write_end(): when copy_folio_from_iter_atomic()\nreturns 0 (e.g. user buffer fault) and the folio is already uptodate,\nthe guard at the top of __iomap_write_end() does not trigger because\n!folio_test_uptodate() is false, and iomap_set_range_dirty() is called\nwith copied == 0.\n\nAdd a !len guard to both functions before the computation, so that a\nzero-length range is a no-op."
    }
  ],
  "id": "CVE-2026-68145",
  "lastModified": "2026-08-17T05:18:14.573",
  "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": "2026-08-10T13:20:00.350",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7037e7bdcd26f46c080b8ce307dee5cb471c4b7c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9c7d8f7c8994c790fca501dc45ce66e7356cbe05"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c5b6a48a8a716a7730e39af1cad083dc4ec955ce"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fb4fad9105c88b1d82f1b3c39e3b6abea8249af6"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-68145 (GCVE-0-2026-68145)

Vulnerability from cvelistv5 – Published: 2026-08-10 11:59 – Updated: 2026-08-17 04:59

Title

iomap: fix out-of-bounds bitmap_set() with zero-length range

Summary

Severity

7.8 (High)


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

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/fb4fad9105c88b1d8…
https://git.kernel.org/stable/c/7037e7bdcd26f46c0…
https://git.kernel.org/stable/c/c5b6a48a8a716a773…
https://git.kernel.org/stable/c/9c7d8f7c8994c790f…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 4ce02c67972211be488408c275c8fbf19faf29b3 , < fb4fad9105c88b1d82f1b3c39e3b6abea8249af6 (git) Affected: 4ce02c67972211be488408c275c8fbf19faf29b3 , < 7037e7bdcd26f46c080b8ce307dee5cb471c4b7c (git) Affected: 4ce02c67972211be488408c275c8fbf19faf29b3 , < c5b6a48a8a716a7730e39af1cad083dc4ec955ce (git) Affected: 4ce02c67972211be488408c275c8fbf19faf29b3 , < 9c7d8f7c8994c790fca501dc45ce66e7356cbe05 (git)
Linux	Linux	Affected: 6.6 Unaffected: 0 , < 6.6 (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.6 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/iomap/buffered-io.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fb4fad9105c88b1d82f1b3c39e3b6abea8249af6",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            },
            {
              "lessThan": "7037e7bdcd26f46c080b8ce307dee5cb471c4b7c",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            },
            {
              "lessThan": "c5b6a48a8a716a7730e39af1cad083dc4ec955ce",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            },
            {
              "lessThan": "9c7d8f7c8994c790fca501dc45ce66e7356cbe05",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/iomap/buffered-io.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.6"
            },
            {
              "lessThan": "6.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niomap: fix out-of-bounds bitmap_set() with zero-length range\n\nifs_set_range_dirty() and ifs_set_range_uptodate() compute last_blk\nas (off + len - 1) \u003e\u003e i_blkbits.  When off is 0 and len is 0, the\nunsigned subtraction underflows to SIZE_MAX, producing a huge\nlast_blk and nr_blks value that causes bitmap_set() to write far\nbeyond the ifs-\u003estate allocation.\n\nRegarding ifs_set_range_uptodate(), it is temporarily safe because len\ncannot be passed in as 0. However, for ifs_set_range_dirty() this is\nreachable from __iomap_write_end(): when copy_folio_from_iter_atomic()\nreturns 0 (e.g. user buffer fault) and the folio is already uptodate,\nthe guard at the top of __iomap_write_end() does not trigger because\n!folio_test_uptodate() is false, and iomap_set_range_dirty() is called\nwith copied == 0.\n\nAdd a !len guard to both functions before the computation, so that a\nzero-length range is a no-op."
        }
      ],
      "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 bug is reached via the buffered write() path through iomap_file_buffered_write() when copy_folio_from_iter_atomic() returns 0; NFS/ksmbd server writes use kernel bvec iterators and do not hit this user-buffer fault path.\nAC:L - An attacker can reliably trigger copied==0 by racing munmap/remap against write() on an already-uptodate folio (TOCTOU after fault_in_iov_iter_readable), controlling both sides of the race on systems where folio size exceeds filesystem block size.\nPR:L - Only standard local write permission to a file on an iomap-backed filesystem (XFS, GFS2, FUSE writeback-cache, zonefs, NTFS) is required; no CAP_SYS_ADMIN or other elevated capability is needed beyond creating/triggering writes to attacker-writable files.\nUI:N - Exploitation requires only the attacker\u0027s own write operations to a writable file; no action by another user or administrator (such as mounting a filesystem or opening a file on the victim\u0027s behalf) is needed.\nS:U - Successful exploitation corrupts host kernel heap memory and enables local privilege escalation within the same kernel security domain; it does not inherently cross VM, container, or IOMMU boundaries.\nC:H - ifs_set_range_dirty() with len==0 underflows to SIZE_MAX and bitmap_set() writes far beyond the small kzalloc_flex(ifs-\u003estate) allocation, corrupting adjacent kmalloc objects in ways that can be leveraged for arbitrary kernel memory disclosure.\nI:H - The out-of-bounds bitmap_set() is a large heap overwrite primitive adjacent to the iomap_folio_state allocation, enabling control of kernel data structures and arbitrary code execution via standard heap exploitation techniques.\nA:H - The massive out-of-bounds write can immediately corrupt critical kernel heap metadata or adjacent objects, causing kernel oops/panic or unrecoverable memory corruption even before full exploitation is attempted."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:59:39.203Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/fb4fad9105c88b1d82f1b3c39e3b6abea8249af6"
        },
        {
          "url": "https://git.kernel.org/stable/c/7037e7bdcd26f46c080b8ce307dee5cb471c4b7c"
        },
        {
          "url": "https://git.kernel.org/stable/c/c5b6a48a8a716a7730e39af1cad083dc4ec955ce"
        },
        {
          "url": "https://git.kernel.org/stable/c/9c7d8f7c8994c790fca501dc45ce66e7356cbe05"
        }
      ],
      "title": "iomap: fix out-of-bounds bitmap_set() with zero-length range",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68145",
    "datePublished": "2026-08-10T11:59:09.721Z",
    "dateReserved": "2026-07-30T09:28:09.371Z",
    "dateUpdated": "2026-08-17T04:59:39.203Z",
    "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.

Detection rules are retrieved from Rulezet.

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.

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FKIE_CVE-2026-68145

CVE-2026-68145 (GCVE-0-2026-68145)

Tags

Sightings

Nomenclature