GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

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

Vulnerability from cvelistv5 – Published: 2026-08-10 11:59 – Updated: 2026-08-23 12:45
VLAI
Title
iomap: fix out-of-bounds bitmap_set() with zero-length range
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.
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: 4ce02c67972211be488408c275c8fbf19faf29b3 , < 48829622212f6b8f49155889aecc818ba28ba680 (git)
Affected: 4ce02c67972211be488408c275c8fbf19faf29b3 , < fb4fad9105c88b1d82f1b3c39e3b6abea8249af6 (git)
Affected: 4ce02c67972211be488408c275c8fbf19faf29b3 , < 7037e7bdcd26f46c080b8ce307dee5cb471c4b7c (git)
Affected: 4ce02c67972211be488408c275c8fbf19faf29b3 , < c5b6a48a8a716a7730e39af1cad083dc4ec955ce (git)
Affected: 4ce02c67972211be488408c275c8fbf19faf29b3 , < 9c7d8f7c8994c790fca501dc45ce66e7356cbe05 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.6
Unaffected: 0 , < 6.6 (semver)
Unaffected: 6.6.153 , ≤ 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)
guessed Create a notification for this product.
Show details on NVD website
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": "48829622212f6b8f49155889aecc818ba28ba680",
              "status": "affected",
              "version": "4ce02c67972211be488408c275c8fbf19faf29b3",
              "versionType": "git"
            },
            {
              "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": "6.6.*",
              "status": "unaffected",
              "version": "6.6.153",
              "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": "6.6.153",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "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": "2026-08-23T12:45:56.875Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/48829622212f6b8f49155889aecc818ba28ba680"
        },
        {
          "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": "2026-08-23T12:45:56.875Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-68145",
      "date": "2026-09-11",
      "epss": "0.00138",
      "percentile": "0.03506"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-68145\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-10T13:20:00.350\",\"lastModified\":\"2026-08-23T13:16:33.943\",\"vulnStatus\":\"Received\",\"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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/iomap/buffered-io.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"4ce02c67972211be488408c275c8fbf19faf29b3\",\"lessThan\":\"48829622212f6b8f49155889aecc818ba28ba680\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"4ce02c67972211be488408c275c8fbf19faf29b3\",\"lessThan\":\"fb4fad9105c88b1d82f1b3c39e3b6abea8249af6\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"4ce02c67972211be488408c275c8fbf19faf29b3\",\"lessThan\":\"7037e7bdcd26f46c080b8ce307dee5cb471c4b7c\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"4ce02c67972211be488408c275c8fbf19faf29b3\",\"lessThan\":\"c5b6a48a8a716a7730e39af1cad083dc4ec955ce\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"4ce02c67972211be488408c275c8fbf19faf29b3\",\"lessThan\":\"9c7d8f7c8994c790fca501dc45ce66e7356cbe05\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/iomap/buffered-io.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.6\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.6\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.153\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.101\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.42\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/48829622212f6b8f49155889aecc818ba28ba680\",\"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\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-09-04T07:52:35+00:00",
      "cve": "CVE-2026-68145",
      "id": "CVE-2026-68145",
      "initial_release_date": "2026-08-10T00:00:00+00:00",
      "product_status:fixed": "612",
      "product_status:known_not_affected": "112",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: iomap: fix out-of-bounds bitmap_set() with zero-length range",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68145.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-09T00:07:00Z",
      "cve": "CVE-2026-68145",
      "id": "CVE-2026-68145",
      "initial_release_date": "2026-08-18T16:56:09Z",
      "product_status:first_fixed": "83",
      "product_status:known_affected": "29",
      "product_status:known_not_affected": "328",
      "product_status:recommended": "52",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-68145",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68145.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.

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.