CVE-2025-22039 (GCVE-0-2025-22039)

Vulnerability from cvelistv5 – Published: 2025-04-16 14:11 – Updated: 2026-08-05 11:56
VLAI
Title
ksmbd: fix overflow in dacloffset bounds check
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix overflow in dacloffset bounds check The dacloffset field was originally typed as int and used in an unchecked addition, which could overflow and bypass the existing bounds check in both smb_check_perm_dacl() and smb_inherit_dacl(). This could result in out-of-bounds memory access and a kernel crash when dereferencing the DACL pointer. This patch converts dacloffset to unsigned int and uses check_add_overflow() to validate access to the DACL.
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 6a9cd9ff0fa2bcc30b2bfb8bdb161eb20e44b9dc (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 6b8d379048b168a0dff5ab1acb975b933f368514 (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 443b373a4df5a2cb9f7b8c4658b2afedeb16397f (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < beff0bc9d69bc8e733f9bca28e2d3df5b3e10e42 (git)
Create a notification for this product.
Linux Linux Affected: 5.15
Unaffected: 0 , < 5.15 (semver)
Unaffected: 6.12.23 , ≤ 6.12.* (semver)
Unaffected: 6.13.11 , ≤ 6.13.* (semver)
Unaffected: 6.14.2 , ≤ 6.14.* (semver)
Unaffected: 6.15 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smbacl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6a9cd9ff0fa2bcc30b2bfb8bdb161eb20e44b9dc",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            },
            {
              "lessThan": "6b8d379048b168a0dff5ab1acb975b933f368514",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            },
            {
              "lessThan": "443b373a4df5a2cb9f7b8c4658b2afedeb16397f",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            },
            {
              "lessThan": "beff0bc9d69bc8e733f9bca28e2d3df5b3e10e42",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smbacl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.23",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.14.*",
              "status": "unaffected",
              "version": "6.14.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.15",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.23",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13.11",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.14.2",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.15",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix overflow in dacloffset bounds check\n\nThe dacloffset field was originally typed as int and used in an\nunchecked addition, which could overflow and bypass the existing\nbounds check in both smb_check_perm_dacl() and smb_inherit_dacl().\n\nThis could result in out-of-bounds memory access and a kernel crash\nwhen dereferencing the DACL pointer.\n\nThis patch converts dacloffset to unsigned int and uses\ncheck_add_overflow() to validate access to the DACL."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - ksmbd is the in-kernel SMB server; the malicious `dacloffset` arrives in an SMB2 SET_INFO security-descriptor payload over TCP/445 and is triggered by a subsequent SMB2 CREATE. No local access is needed.\nAC:L - The attacker fully controls the 32-bit `dacloffset` field and simply picks a value in 0xFFFFFFF8\u20130xFFFFFFFF to bypass the check; there is no race, no memory-layout guessing, and the trigger is two ordinary SMB2 requests that can be repeated at will.\nPR:L - The path requires an established SMB2 session and tree connect plus an open handle with write access, so valid (even minimal, non-admin) share credentials are needed \u2014 this is squarely post-authentication, not a handshake path.\nUI:N - The attacker plants the crafted security descriptor and re-opens the file entirely on their own; no action by an administrator or any other client is involved.\nS:U - The out-of-bounds access and resulting crash are confined to the kernel\u0027s own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `pdacl` is dereferenced roughly 4 GiB beyond a small kmalloc\u0027d buffer and the ACE walk then reads further from there \u2014 an unbounded kernel-memory read, whose bytes are OR\u0027d into `granted` and returned to the client in the maximal-access create context, and are persisted into on-disk ACLs by smb_inherit_dacl.\nI:H - The out-of-bounds bytes directly determine the DACL verdict and the granted access mask stored in `fp-\u003edaccess` (including WRITE_DAC/DELETE/GENERIC_ALL), so the Windows ACL enforcement layer can be defeated, and smb_inherit_dacl writes out-of-bounds heap contents into the security.NTACL xattr of newly created files.\nA:H - Dereferencing a pointer ~4 GiB past the allocation faults on any system where that address is not backed by the direct map, producing a kernel oops in the ksmbd worker (a panic with panic_on_oops); the attacker can repeat it at will."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T11:56:12.156Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6a9cd9ff0fa2bcc30b2bfb8bdb161eb20e44b9dc"
        },
        {
          "url": "https://git.kernel.org/stable/c/6b8d379048b168a0dff5ab1acb975b933f368514"
        },
        {
          "url": "https://git.kernel.org/stable/c/443b373a4df5a2cb9f7b8c4658b2afedeb16397f"
        },
        {
          "url": "https://git.kernel.org/stable/c/beff0bc9d69bc8e733f9bca28e2d3df5b3e10e42"
        }
      ],
      "title": "ksmbd: fix overflow in dacloffset bounds check",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-22039",
    "datePublished": "2025-04-16T14:11:56.975Z",
    "dateReserved": "2024-12-29T08:45:45.809Z",
    "dateUpdated": "2026-08-05T11:56:12.156Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-22039",
      "date": "2026-08-09",
      "epss": "0.00664",
      "percentile": "0.48313"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-22039\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-04-16T15:15:56.500\",\"lastModified\":\"2026-07-30T06:22:05.283\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nksmbd: fix overflow in dacloffset bounds check\\n\\nThe dacloffset field was originally typed as int and used in an\\nunchecked addition, which could overflow and bypass the existing\\nbounds check in both smb_check_perm_dacl() and smb_inherit_dacl().\\n\\nThis could result in out-of-bounds memory access and a kernel crash\\nwhen dereferencing the DACL pointer.\\n\\nThis patch converts dacloffset to unsigned int and uses\\ncheck_add_overflow() to validate access to the DACL.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ksmbd: correcci\u00f3n de desbordamiento en la comprobaci\u00f3n de los l\u00edmites de dacloffset. El campo dacloffset se tipific\u00f3 originalmente como int y se us\u00f3 en una adici\u00f3n sin comprobar, lo que podr\u00eda desbordarse y omitir la comprobaci\u00f3n de los l\u00edmites existente tanto en smb_check_perm_dacl() como en smb_inherit_dacl(). Esto podr\u00eda provocar un acceso a memoria fuera de los l\u00edmites y un fallo del kernel al desreferenciar el puntero DACL. Este parche convierte dacloffset a unsigned int y utiliza check_add_overflow() para validar el acceso a la DACL.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/smb/server/smbacl.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"0626e6641f6b467447c81dd7678a69c66f7746cf\",\"lessThan\":\"6a9cd9ff0fa2bcc30b2bfb8bdb161eb20e44b9dc\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0626e6641f6b467447c81dd7678a69c66f7746cf\",\"lessThan\":\"6b8d379048b168a0dff5ab1acb975b933f368514\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0626e6641f6b467447c81dd7678a69c66f7746cf\",\"lessThan\":\"443b373a4df5a2cb9f7b8c4658b2afedeb16397f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0626e6641f6b467447c81dd7678a69c66f7746cf\",\"lessThan\":\"beff0bc9d69bc8e733f9bca28e2d3df5b3e10e42\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/smb/server/smbacl.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.15\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.15\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.23\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.13.11\",\"lessThanOrEqual\":\"6.13.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.14.2\",\"lessThanOrEqual\":\"6.14.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.15\",\"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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":5.9},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.2}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-125\"},{\"lang\":\"en\",\"value\":\"CWE-190\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"5.15\",\"versionEndExcluding\":\"6.12.23\",\"matchCriteriaId\":\"1FDF0290-DECC-4633-9F68-856CD6ABA9A5\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.13.11\",\"matchCriteriaId\":\"E7E864B0-8C00-4679-BA55-659B4C9C3AD3\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.14\",\"versionEndExcluding\":\"6.14.2\",\"matchCriteriaId\":\"FADAE5D8-4808-442C-B218-77B2CE8780A0\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/443b373a4df5a2cb9f7b8c4658b2afedeb16397f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/6a9cd9ff0fa2bcc30b2bfb8bdb161eb20e44b9dc\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/6b8d379048b168a0dff5ab1acb975b933f368514\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/beff0bc9d69bc8e733f9bca28e2d3df5b3e10e42\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-30T10:30:36+00:00",
      "cve": "CVE-2025-22039",
      "id": "CVE-2025-22039",
      "initial_release_date": "2025-04-16T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ksmbd: fix overflow in dacloffset bounds check",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-22039.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-02T16:47:22Z",
      "cve": "CVE-2025-22039",
      "id": "CVE-2025-22039",
      "initial_release_date": "2025-04-18T23:20:25Z",
      "product_status:known_not_affected": "453",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-22039",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-22039.json",
      "version": "9"
    }
  }
}



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.