CVE-2026-43379 (GCVE-0-2026-43379)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:21 – Updated: 2026-05-08 14:21
VLAI?
Title
ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close() opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is being accessed after rcu_read_unlock() has been called. This creates a race condition where the memory could be freed by a concurrent writer between the unlock and the subsequent pointer dereferences (opinfo->is_lease, etc.), leading to a use-after-free.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 27b40b7bfcd121fe13a150ffe11957630cf49246 , < bf4d66d72e4a9e268c1012c331ce9eaedb5e2086 (git)
Affected: 5fb282ba4fef8985a5acf2b32681f2ec07732561 , < 960699317d39f46611f4ebeb69edc567c1f4e6b6 (git)
Affected: 5fb282ba4fef8985a5acf2b32681f2ec07732561 , < dbbd328cf58261ca239756fe1c0d10c9518d3399 (git)
Affected: 5fb282ba4fef8985a5acf2b32681f2ec07732561 , < b3568347c51c46e2cabc356bc34676df98296619 (git)
Affected: 5fb282ba4fef8985a5acf2b32681f2ec07732561 , < eac3361e3d5dd8067b3258c69615888eb45e9f25 (git)
Create a notification for this product.
    Linux Linux Affected: 6.9
Unaffected: 0 , < 6.9 (semver)
Unaffected: 6.6.130 , ≤ 6.6.* (semver)
Unaffected: 6.12.78 , ≤ 6.12.* (semver)
Unaffected: 6.18.19 , ≤ 6.18.* (semver)
Unaffected: 6.19.9 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (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/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bf4d66d72e4a9e268c1012c331ce9eaedb5e2086",
              "status": "affected",
              "version": "27b40b7bfcd121fe13a150ffe11957630cf49246",
              "versionType": "git"
            },
            {
              "lessThan": "960699317d39f46611f4ebeb69edc567c1f4e6b6",
              "status": "affected",
              "version": "5fb282ba4fef8985a5acf2b32681f2ec07732561",
              "versionType": "git"
            },
            {
              "lessThan": "dbbd328cf58261ca239756fe1c0d10c9518d3399",
              "status": "affected",
              "version": "5fb282ba4fef8985a5acf2b32681f2ec07732561",
              "versionType": "git"
            },
            {
              "lessThan": "b3568347c51c46e2cabc356bc34676df98296619",
              "status": "affected",
              "version": "5fb282ba4fef8985a5acf2b32681f2ec07732561",
              "versionType": "git"
            },
            {
              "lessThan": "eac3361e3d5dd8067b3258c69615888eb45e9f25",
              "status": "affected",
              "version": "5fb282ba4fef8985a5acf2b32681f2ec07732561",
              "versionType": "git"
            }
          ]
        },
        {
          "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": "6.6.130",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.78",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.9",
              "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": "6.6.130",
                  "versionStartIncluding": "6.6.32",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.78",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.19",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.9",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "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 use-after-free in smb_lazy_parent_lease_break_close()\n\nopinfo pointer obtained via rcu_dereference(fp-\u003ef_opinfo) is being\naccessed after rcu_read_unlock() has been called. This creates a\nrace condition where the memory could be freed by a concurrent\nwriter between the unlock and the subsequent pointer dereferences\n(opinfo-\u003eis_lease, etc.), leading to a use-after-free."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-08T14:21:28.027Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/bf4d66d72e4a9e268c1012c331ce9eaedb5e2086"
        },
        {
          "url": "https://git.kernel.org/stable/c/960699317d39f46611f4ebeb69edc567c1f4e6b6"
        },
        {
          "url": "https://git.kernel.org/stable/c/dbbd328cf58261ca239756fe1c0d10c9518d3399"
        },
        {
          "url": "https://git.kernel.org/stable/c/b3568347c51c46e2cabc356bc34676df98296619"
        },
        {
          "url": "https://git.kernel.org/stable/c/eac3361e3d5dd8067b3258c69615888eb45e9f25"
        }
      ],
      "title": "ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43379",
    "datePublished": "2026-05-08T14:21:28.027Z",
    "dateReserved": "2026-05-01T14:12:56.006Z",
    "dateUpdated": "2026-05-08T14:21:28.027Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-43379",
      "date": "2026-05-09",
      "epss": "0.00018",
      "percentile": "0.04917"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-43379\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-08T15:16:49.100\",\"lastModified\":\"2026-05-08T15:16:49.100\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()\\n\\nopinfo pointer obtained via rcu_dereference(fp-\u003ef_opinfo) is being\\naccessed after rcu_read_unlock() has been called. This creates a\\nrace condition where the memory could be freed by a concurrent\\nwriter between the unlock and the subsequent pointer dereferences\\n(opinfo-\u003eis_lease, etc.), leading to a use-after-free.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/960699317d39f46611f4ebeb69edc567c1f4e6b6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b3568347c51c46e2cabc356bc34676df98296619\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/bf4d66d72e4a9e268c1012c331ce9eaedb5e2086\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/dbbd328cf58261ca239756fe1c0d10c9518d3399\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/eac3361e3d5dd8067b3258c69615888eb45e9f25\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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.