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FKIE_CVE-2025-40039

Vulnerability from fkie_nvd - Published: 2025-10-28 12:15 - Updated: 2026-07-30 06:24
Severity
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.7 (Medium) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix race condition in RPC handle list access The 'sess->rpc_handle_list' XArray manages RPC handles within a ksmbd session. Access to this list is intended to be protected by 'sess->rpc_lock' (an rw_semaphore). However, the locking implementation was flawed, leading to potential race conditions. In ksmbd_session_rpc_open(), the code incorrectly acquired only a read lock before calling xa_store() and xa_erase(). Since these operations modify the XArray structure, a write lock is required to ensure exclusive access and prevent data corruption from concurrent modifications. Furthermore, ksmbd_session_rpc_method() accessed the list using xa_load() without holding any lock at all. This could lead to reading inconsistent data or a potential use-after-free if an entry is concurrently removed and the pointer is dereferenced. Fix these issues by: 1. Using down_write() and up_write() in ksmbd_session_rpc_open() to ensure exclusive access during XArray modification, and ensuring the lock is correctly released on error paths. 2. Adding down_read() and up_read() in ksmbd_session_rpc_method() to safely protect the lookup.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/305853cce379407090a73b38c5de5ba748893aeePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5cc679ba0f4505936124cd4179ba66bb0a4bd9f3Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/69674b029002b1d90b655f014bdf64f404efa54dPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6b615a8fb3af0baf8126cde3d4fee97d57222ffcPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6bd7e0e55dcea2cf0d391bbc21c2eb069b4be3e1Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "69674b029002b1d90b655f014bdf64f404efa54d",
              "status": "affected",
              "version": "a4348710a7267705b75692dc1a000920481d1d92",
              "versionType": "git"
            },
            {
              "lessThan": "6b615a8fb3af0baf8126cde3d4fee97d57222ffc",
              "status": "affected",
              "version": "b685757c7b08d5073046fb379be965fd6c06aafc",
              "versionType": "git"
            },
            {
              "lessThan": "5cc679ba0f4505936124cd4179ba66bb0a4bd9f3",
              "status": "affected",
              "version": "b685757c7b08d5073046fb379be965fd6c06aafc",
              "versionType": "git"
            },
            {
              "lessThan": "6bd7e0e55dcea2cf0d391bbc21c2eb069b4be3e1",
              "status": "affected",
              "version": "b685757c7b08d5073046fb379be965fd6c06aafc",
              "versionType": "git"
            },
            {
              "lessThan": "305853cce379407090a73b38c5de5ba748893aee",
              "status": "affected",
              "version": "b685757c7b08d5073046fb379be965fd6c06aafc",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1f485b54d04a920723984062c912174330a05178",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "052b41ef2abe274f068e892aee81406f11bd1f3a",
              "versionType": "git"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.145",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.3"
            },
            {
              "lessThan": "6.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.123",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B98C9201-BF17-4E2C-84FF-75EE2AA94DC5",
              "versionEndExcluding": "5.16",
              "versionStartIncluding": "5.15.145",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "163E72B5-0F5D-49E2-AAEA-F11E02D730AD",
              "versionEndExcluding": "6.2",
              "versionStartIncluding": "6.1.71",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F522E23F-2E27-4FDC-A9A5-FE6B600E1D7D",
              "versionEndExcluding": "6.6.123",
              "versionStartIncluding": "6.3",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "A9028AC3-C3E8-4D5D-9235-DE8859551F7E",
              "versionEndExcluding": "6.12.53",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "F55A160F-1578-4C10-ABCB-F90B7E146ED8",
              "versionEndExcluding": "6.17.3",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: Fix race condition in RPC handle list access\n\nThe \u0027sess-\u003erpc_handle_list\u0027 XArray manages RPC handles within a ksmbd\nsession. Access to this list is intended to be protected by\n\u0027sess-\u003erpc_lock\u0027 (an rw_semaphore). However, the locking implementation was\nflawed, leading to potential race conditions.\n\nIn ksmbd_session_rpc_open(), the code incorrectly acquired only a read lock\nbefore calling xa_store() and xa_erase(). Since these operations modify\nthe XArray structure, a write lock is required to ensure exclusive access\nand prevent data corruption from concurrent modifications.\n\nFurthermore, ksmbd_session_rpc_method() accessed the list using xa_load()\nwithout holding any lock at all. This could lead to reading inconsistent\ndata or a potential use-after-free if an entry is concurrently removed and\nthe pointer is dereferenced.\n\nFix these issues by:\n1. Using down_write() and up_write() in ksmbd_session_rpc_open()\n   to ensure exclusive access during XArray modification, and ensuring\n   the lock is correctly released on error paths.\n2. Adding down_read() and up_read() in ksmbd_session_rpc_method()\n   to safely protect the lookup."
    }
  ],
  "id": "CVE-2025-40039",
  "lastModified": "2026-07-30T06:24:07.150",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2025-10-28T12:15:37.847",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/305853cce379407090a73b38c5de5ba748893aee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/5cc679ba0f4505936124cd4179ba66bb0a4bd9f3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/69674b029002b1d90b655f014bdf64f404efa54d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/6b615a8fb3af0baf8126cde3d4fee97d57222ffc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/6bd7e0e55dcea2cf0d391bbc21c2eb069b4be3e1"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-362"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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