Vulnerability-Lookup

GHSA-F75P-6Q8J-P2F2

Vulnerability from github – Published: 2026-04-22 09:31 – Updated: 2026-04-22 09:31

Details

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

ksmbd: fix OOB write in QUERY_INFO for compound requests

When a compound request such as READ + QUERY_INFO(Security) is received, and the first command (READ) consumes most of the response buffer, ksmbd could write beyond the allocated buffer while building a security descriptor.

The root cause was that smb2_get_info_sec() checked buffer space using ppntsd_size from xattr, while build_sec_desc() often synthesized a significantly larger descriptor from POSIX ACLs.

This patch introduces smb_acl_sec_desc_scratch_len() to accurately compute the final descriptor size beforehand, performs proper buffer checking with smb2_calc_max_out_buf_len(), and uses exact-sized allocation + iov pinning.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-31432"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-22T09:16:21Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix OOB write in QUERY_INFO for compound requests\n\nWhen a compound request such as READ + QUERY_INFO(Security) is received,\nand the first command (READ) consumes most of the response buffer,\nksmbd could write beyond the allocated buffer while building a security\ndescriptor.\n\nThe root cause was that smb2_get_info_sec() checked buffer space using\nppntsd_size from xattr, while build_sec_desc() often synthesized a\nsignificantly larger descriptor from POSIX ACLs.\n\nThis patch introduces smb_acl_sec_desc_scratch_len() to accurately\ncompute the final descriptor size beforehand, performs proper buffer\nchecking with smb2_calc_max_out_buf_len(), and uses exact-sized\nallocation + iov pinning.",
  "id": "GHSA-f75p-6q8j-p2f2",
  "modified": "2026-04-22T09:31:32Z",
  "published": "2026-04-22T09:31:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31432"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/075ea208c648cc2bcd616295b711d3637c61de45"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/515c2daab46021221bdf406bef19bc90a44ec617"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d48c64fb80ad78b3dd29fb7d79b6ec7bd72bfc09"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fda9522ed6afaec45cabc198d8492270c394c7bc"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-31432 (GCVE-0-2026-31432)

Vulnerability from cvelistv5 – Published: 2026-04-22 08:15 – Updated: 2026-04-22 08:15

Title

ksmbd: fix OOB write in QUERY_INFO for compound requests

Summary

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix OOB write in QUERY_INFO for compound requests When a compound request such as READ + QUERY_INFO(Security) is received, and the first command (READ) consumes most of the response buffer, ksmbd could write beyond the allocated buffer while building a security descriptor. The root cause was that smb2_get_info_sec() checked buffer space using ppntsd_size from xattr, while build_sec_desc() often synthesized a significantly larger descriptor from POSIX ACLs. This patch introduces smb_acl_sec_desc_scratch_len() to accurately compute the final descriptor size beforehand, performs proper buffer checking with smb2_calc_max_out_buf_len(), and uses exact-sized allocation + iov pinning.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/d48c64fb80ad78b3d…
	https://git.kernel.org/stable/c/075ea208c648cc2bc…
	https://git.kernel.org/stable/c/515c2daab46021221…
	https://git.kernel.org/stable/c/fda9522ed6afaec45…

Impacted products

Vendor

Product

Version

Linux

Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < d48c64fb80ad78b3dd29fb7d79b6ec7bd72bfc09 (git)
Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < 075ea208c648cc2bcd616295b711d3637c61de45 (git)
Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < 515c2daab46021221bdf406bef19bc90a44ec617 (git)
Affected: e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d , < fda9522ed6afaec45cabc198d8492270c394c7bc (git)
Affected: f2283680a80571ca82d710bc6ecd8f8beac67d63 (git)
Affected: 9f297df20d93411c0b4ddad7f88ba04a7cd36e77 (git)

Linux

Affected: 6.6
Unaffected: 0 , < 6.6 (semver)
Unaffected: 6.12.81 , ≤ 6.12.* (semver)
Unaffected: 6.18.22 , ≤ 6.18.* (semver)
Unaffected: 6.19.12 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c",
            "fs/smb/server/smbacl.c",
            "fs/smb/server/smbacl.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
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              "versionType": "git"
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              "version": "e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d",
              "versionType": "git"
            },
            {
              "lessThan": "515c2daab46021221bdf406bef19bc90a44ec617",
              "status": "affected",
              "version": "e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d",
              "versionType": "git"
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            {
              "lessThan": "fda9522ed6afaec45cabc198d8492270c394c7bc",
              "status": "affected",
              "version": "e2b76ab8b5c9327ab2dae6da05d0752eb2f4771d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f2283680a80571ca82d710bc6ecd8f8beac67d63",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9f297df20d93411c0b4ddad7f88ba04a7cd36e77",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c",
            "fs/smb/server/smbacl.c",
            "fs/smb/server/smbacl.h"
          ],
          "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": "6.12.81",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.22",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.81",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
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                },
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      "descriptions": [
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix OOB write in QUERY_INFO for compound requests\n\nWhen a compound request such as READ + QUERY_INFO(Security) is received,\nand the first command (READ) consumes most of the response buffer,\nksmbd could write beyond the allocated buffer while building a security\ndescriptor.\n\nThe root cause was that smb2_get_info_sec() checked buffer space using\nppntsd_size from xattr, while build_sec_desc() often synthesized a\nsignificantly larger descriptor from POSIX ACLs.\n\nThis patch introduces smb_acl_sec_desc_scratch_len() to accurately\ncompute the final descriptor size beforehand, performs proper buffer\nchecking with smb2_calc_max_out_buf_len(), and uses exact-sized\nallocation + iov pinning."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-22T08:15:10.873Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/d48c64fb80ad78b3dd29fb7d79b6ec7bd72bfc09"
        },
        {
          "url": "https://git.kernel.org/stable/c/075ea208c648cc2bcd616295b711d3637c61de45"
        },
        {
          "url": "https://git.kernel.org/stable/c/515c2daab46021221bdf406bef19bc90a44ec617"
        },
        {
          "url": "https://git.kernel.org/stable/c/fda9522ed6afaec45cabc198d8492270c394c7bc"
        }
      ],
      "title": "ksmbd: fix OOB write in QUERY_INFO for compound requests",
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        "engine": "bippy-1.2.0"
      }
    }
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31432",
    "datePublished": "2026-04-22T08:15:10.873Z",
    "dateReserved": "2026-03-09T15:48:24.089Z",
    "dateUpdated": "2026-04-22T08:15:10.873Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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.

Action not permitted

GHSA-F75P-6Q8J-P2F2

CVE-2026-31432 (GCVE-0-2026-31432)

Tags

Sightings

Nomenclature