Vulnerability-Lookup

FKIE_CVE-2026-64141

Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-20 15:17

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in compare_guid_key() session_fd_check() walks the per-inode m_op_list during durable-handle session teardown and sets op->conn = NULL for every opinfo whose conn matched the closing session's connection. The matching opinfo, however, stays linked in its per-ClientGuid lease_table_list entry's lb->lease_list because destroy_lease_table() only runs on full TCP-connection teardown, not on SESSION_LOGOFF. If the same TCP connection then negotiates a fresh session with the same ClientGuid (ClientGuid is bound to NEGOTIATE, not the session, and is unchanged across LOGOFF + SETUP) and issues a SMB2 CREATE with a lease context on a different inode, find_same_lease_key() walks lb->lease_list, reaches the stale opinfo, and calls compare_guid_key(), which unconditionally dereferences opinfo->conn->ClientGUID. The conn pointer is NULL and the kernel panics. Reproducer requires only a successful SMB2 SESSION_SETUP and a share configured with 'durable handles = yes'. KASAN report on mainline 70390501d194: general protection fault, probably for non-canonical address 0xdffffc0000000069: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000348-0x000000000000034f] Workqueue: ksmbd-io handle_ksmbd_work RIP: 0010:bcmp+0x5b/0x230 Call Trace: compare_guid_key+0x4b/0xd0 find_same_lease_key+0x324/0x690 smb2_open+0x6aea/0x8e60 handle_ksmbd_work+0x796/0xee0 ... Faulting address 0x348 is the offset of ClientGUID within struct ksmbd_conn, confirming opinfo->conn was NULL. Read opinfo->conn once and bail out if it has been cleared by a concurrent session_fd_check(). A half-detached opinfo cannot be the owner of an active lease, so returning 0 is the correct match result.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0836081b394ca074d1b910f2b990ff7b4b4404c7
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/4b83cbc4c15f09b000cc06f033f64b0824b6dc87
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/af86896ca3239e25a6bd7d352213371265073d38
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e43cb36d4d7827710cfcd48e95e29a507f0d87be

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e43cb36d4d7827710cfcd48e95e29a507f0d87be",
              "status": "affected",
              "version": "8df4bcdb0a4232192b2445256c39b787d58ef14d",
              "versionType": "git"
            },
            {
              "lessThan": "0836081b394ca074d1b910f2b990ff7b4b4404c7",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "af86896ca3239e25a6bd7d352213371265073d38",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "4b83cbc4c15f09b000cc06f033f64b0824b6dc87",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "6.6.142",
              "status": "affected",
              "version": "6.6.32",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.9"
            },
            {
              "lessThan": "6.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.142",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "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\nksmbd: fix null pointer dereference in compare_guid_key()\n\nsession_fd_check() walks the per-inode m_op_list during durable-handle\nsession teardown and sets op-\u003econn = NULL for every opinfo whose conn\nmatched the closing session\u0027s connection. The matching opinfo, however,\nstays linked in its per-ClientGuid lease_table_list entry\u0027s lb-\u003elease_list\nbecause destroy_lease_table() only runs on full TCP-connection teardown,\nnot on SESSION_LOGOFF.\n\nIf the same TCP connection then negotiates a fresh session with the\nsame ClientGuid (ClientGuid is bound to NEGOTIATE, not the session, and\nis unchanged across LOGOFF + SETUP) and issues a SMB2 CREATE with a\nlease context on a different inode, find_same_lease_key() walks\nlb-\u003elease_list, reaches the stale opinfo, and calls compare_guid_key(),\nwhich unconditionally dereferences opinfo-\u003econn-\u003eClientGUID. The conn\npointer is NULL and the kernel panics.\n\nReproducer requires only a successful SMB2 SESSION_SETUP and a share\nconfigured with \u0027durable handles = yes\u0027. KASAN report on mainline\n70390501d194:\n\n  general protection fault, probably for non-canonical address\n  0xdffffc0000000069: 0000 [#1] SMP KASAN PTI\n  KASAN: null-ptr-deref in range [0x0000000000000348-0x000000000000034f]\n  Workqueue: ksmbd-io handle_ksmbd_work\n  RIP: 0010:bcmp+0x5b/0x230\n  Call Trace:\n   compare_guid_key+0x4b/0xd0\n   find_same_lease_key+0x324/0x690\n   smb2_open+0x6aea/0x8e60\n   handle_ksmbd_work+0x796/0xee0\n   ...\n\nFaulting address 0x348 is the offset of ClientGUID within struct\nksmbd_conn, confirming opinfo-\u003econn was NULL.\n\nRead opinfo-\u003econn once and bail out if it has been cleared by a\nconcurrent session_fd_check(). A half-detached opinfo cannot be the\nowner of an active lease, so returning 0 is the correct match result."
    }
  ],
  "id": "CVE-2026-64141",
  "lastModified": "2026-07-20T15:17:12.150",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T16:17:55.983",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0836081b394ca074d1b910f2b990ff7b4b4404c7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4b83cbc4c15f09b000cc06f033f64b0824b6dc87"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/af86896ca3239e25a6bd7d352213371265073d38"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e43cb36d4d7827710cfcd48e95e29a507f0d87be"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-64141 (GCVE-0-2026-64141)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:40 – Updated: 2026-07-20 13:43

Title

ksmbd: fix null pointer dereference in compare_guid_key()

Summary

Severity

7.5 (High)


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

Assigner

Linux

References

5 references

URL	Tags
https://git.kernel.org/stable/c/e43cb36d4d7827710…
https://git.kernel.org/stable/c/0836081b394ca074d…
https://git.kernel.org/stable/c/cd5c1b75d2f454f62…
https://git.kernel.org/stable/c/af86896ca3239e25a…
https://git.kernel.org/stable/c/4b83cbc4c15f09b00…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8df4bcdb0a4232192b2445256c39b787d58ef14d , < e43cb36d4d7827710cfcd48e95e29a507f0d87be (git) Affected: c8efcc786146a951091588e5fa7e3c754850cb3c , < 0836081b394ca074d1b910f2b990ff7b4b4404c7 (git) Affected: c8efcc786146a951091588e5fa7e3c754850cb3c , < cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad (git) Affected: c8efcc786146a951091588e5fa7e3c754850cb3c , < af86896ca3239e25a6bd7d352213371265073d38 (git) Affected: c8efcc786146a951091588e5fa7e3c754850cb3c , < 4b83cbc4c15f09b000cc06f033f64b0824b6dc87 (git) Affected: 6.6.32 , < 6.6.142 (semver)
Linux	Linux	Affected: 6.9 Unaffected: 0 , < 6.9 (semver) Unaffected: 6.6.142 , ≤ 6.6.* (semver) Unaffected: 6.12.92 , ≤ 6.12.* (semver) Unaffected: 6.18.34 , ≤ 6.18.* (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e43cb36d4d7827710cfcd48e95e29a507f0d87be",
              "status": "affected",
              "version": "8df4bcdb0a4232192b2445256c39b787d58ef14d",
              "versionType": "git"
            },
            {
              "lessThan": "0836081b394ca074d1b910f2b990ff7b4b4404c7",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "af86896ca3239e25a6bd7d352213371265073d38",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "4b83cbc4c15f09b000cc06f033f64b0824b6dc87",
              "status": "affected",
              "version": "c8efcc786146a951091588e5fa7e3c754850cb3c",
              "versionType": "git"
            },
            {
              "lessThan": "6.6.142",
              "status": "affected",
              "version": "6.6.32",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.9"
            },
            {
              "lessThan": "6.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.142",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.142",
                  "versionStartIncluding": "6.6.32",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.92",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.34",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.11",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix null pointer dereference in compare_guid_key()\n\nsession_fd_check() walks the per-inode m_op_list during durable-handle\nsession teardown and sets op-\u003econn = NULL for every opinfo whose conn\nmatched the closing session\u0027s connection. The matching opinfo, however,\nstays linked in its per-ClientGuid lease_table_list entry\u0027s lb-\u003elease_list\nbecause destroy_lease_table() only runs on full TCP-connection teardown,\nnot on SESSION_LOGOFF.\n\nIf the same TCP connection then negotiates a fresh session with the\nsame ClientGuid (ClientGuid is bound to NEGOTIATE, not the session, and\nis unchanged across LOGOFF + SETUP) and issues a SMB2 CREATE with a\nlease context on a different inode, find_same_lease_key() walks\nlb-\u003elease_list, reaches the stale opinfo, and calls compare_guid_key(),\nwhich unconditionally dereferences opinfo-\u003econn-\u003eClientGUID. The conn\npointer is NULL and the kernel panics.\n\nReproducer requires only a successful SMB2 SESSION_SETUP and a share\nconfigured with \u0027durable handles = yes\u0027. KASAN report on mainline\n70390501d194:\n\n  general protection fault, probably for non-canonical address\n  0xdffffc0000000069: 0000 [#1] SMP KASAN PTI\n  KASAN: null-ptr-deref in range [0x0000000000000348-0x000000000000034f]\n  Workqueue: ksmbd-io handle_ksmbd_work\n  RIP: 0010:bcmp+0x5b/0x230\n  Call Trace:\n   compare_guid_key+0x4b/0xd0\n   find_same_lease_key+0x324/0x690\n   smb2_open+0x6aea/0x8e60\n   handle_ksmbd_work+0x796/0xee0\n   ...\n\nFaulting address 0x348 is the offset of ClientGUID within struct\nksmbd_conn, confirming opinfo-\u003econn was NULL.\n\nRead opinfo-\u003econn once and bail out if it has been cleared by a\nconcurrent session_fd_check(). A half-detached opinfo cannot be the\nowner of an active lease, so returning 0 is the correct match result."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-20T13:43:45.317Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e43cb36d4d7827710cfcd48e95e29a507f0d87be"
        },
        {
          "url": "https://git.kernel.org/stable/c/0836081b394ca074d1b910f2b990ff7b4b4404c7"
        },
        {
          "url": "https://git.kernel.org/stable/c/cd5c1b75d2f454f625d7dc55bd3ae21d0855f6ad"
        },
        {
          "url": "https://git.kernel.org/stable/c/af86896ca3239e25a6bd7d352213371265073d38"
        },
        {
          "url": "https://git.kernel.org/stable/c/4b83cbc4c15f09b000cc06f033f64b0824b6dc87"
        }
      ],
      "title": "ksmbd: fix null pointer dereference in compare_guid_key()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64141",
    "datePublished": "2026-07-19T15:40:33.890Z",
    "dateReserved": "2026-07-19T07:54:57.037Z",
    "dateUpdated": "2026-07-20T13:43:45.317Z",
    "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.

Action not permitted

FKIE_CVE-2026-64141

CVE-2026-64141 (GCVE-0-2026-64141)

Tags

Sightings

Nomenclature