CVE-2026-53393 (GCVE-0-2026-53393)

Vulnerability from cvelistv5 – Published: 2026-07-19 12:01 – Updated: 2026-07-19 12:01
VLAI
Title
nfsd: reset write verifier on deferred writeback errors
Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: reset write verifier on deferred writeback errors nfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to detect deferred writeback errors, but neither rotates the server's write verifier (nn->writeverf) when this check fails. Every other durable-storage-failure path in these functions calls commit_reset_write_verifier() before returning an error. The missing rotation means clients holding UNSTABLE write data under the current verifier will COMMIT, receive the unchanged verifier back, and conclude their data is durable — silently dropping data that failed writeback. This violates the UNSTABLE+COMMIT durability contract (RFC 1813 §3.3.7, RFC 8881 §18.32). Add commit_reset_write_verifier() calls at both filemap_check_wb_err() error sites, matching the pattern used by adjacent error paths in the same functions. The helper already filters -EAGAIN and -ESTALE internally, so the calls are unconditionally safe.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb , < 1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e (git)
Affected: 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb , < 4367afc119c51e17a616f6908772b7e2c2c4013f (git)
Affected: 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb , < b027cca33c97354149fcc0ddeede4525c41093cd (git)
Affected: 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb , < 2090b05803faab8a9fa62fbff871007862cac1b7 (git)
Affected: f14816f2f928c560d28ba344af689f56efcd6f55 (git)
Affected: 3145fe0ebb16e1715ad541a301bc6675c8375fcd (git)
Affected: 5.10.124 , < 5.11 (semver)
Affected: 5.15.49 , < 5.16 (semver)
Create a notification for this product.
Linux Linux Affected: 5.17
Unaffected: 0 , < 5.17 (semver)
Unaffected: 6.12.95 , ≤ 6.12.* (semver)
Unaffected: 6.18.38 , ≤ 6.18.* (semver)
Unaffected: 7.1.3 , ≤ 7.1.* (semver)
Unaffected: 7.2-rc1 , ≤ * (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/nfsd/vfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e",
              "status": "affected",
              "version": "555dbf1a9aac6d3150c8b52fa35f768a692f4eeb",
              "versionType": "git"
            },
            {
              "lessThan": "4367afc119c51e17a616f6908772b7e2c2c4013f",
              "status": "affected",
              "version": "555dbf1a9aac6d3150c8b52fa35f768a692f4eeb",
              "versionType": "git"
            },
            {
              "lessThan": "b027cca33c97354149fcc0ddeede4525c41093cd",
              "status": "affected",
              "version": "555dbf1a9aac6d3150c8b52fa35f768a692f4eeb",
              "versionType": "git"
            },
            {
              "lessThan": "2090b05803faab8a9fa62fbff871007862cac1b7",
              "status": "affected",
              "version": "555dbf1a9aac6d3150c8b52fa35f768a692f4eeb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f14816f2f928c560d28ba344af689f56efcd6f55",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "3145fe0ebb16e1715ad541a301bc6675c8375fcd",
              "versionType": "git"
            },
            {
              "lessThan": "5.11",
              "status": "affected",
              "version": "5.10.124",
              "versionType": "semver"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.49",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/vfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "lessThan": "5.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.95",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.38",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.95",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.38",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.3",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2-rc1",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.10.124",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.15.49",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: reset write verifier on deferred writeback errors\n\nnfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to\ndetect deferred writeback errors, but neither rotates the server\u0027s write\nverifier (nn-\u003ewriteverf) when this check fails. Every other\ndurable-storage-failure path in these functions calls\ncommit_reset_write_verifier() before returning an error.\n\nThe missing rotation means clients holding UNSTABLE write data under the\ncurrent verifier will COMMIT, receive the unchanged verifier back, and\nconclude their data is durable \u2014 silently dropping data that failed\nwriteback. This violates the UNSTABLE+COMMIT durability contract\n(RFC 1813 \u00a73.3.7, RFC 8881 \u00a718.32).\n\nAdd commit_reset_write_verifier() calls at both filemap_check_wb_err()\nerror sites, matching the pattern used by adjacent error paths in the\nsame functions. The helper already filters -EAGAIN and -ESTALE\ninternally, so the calls are unconditionally safe."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-19T12:01:56.684Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e"
        },
        {
          "url": "https://git.kernel.org/stable/c/4367afc119c51e17a616f6908772b7e2c2c4013f"
        },
        {
          "url": "https://git.kernel.org/stable/c/b027cca33c97354149fcc0ddeede4525c41093cd"
        },
        {
          "url": "https://git.kernel.org/stable/c/2090b05803faab8a9fa62fbff871007862cac1b7"
        }
      ],
      "title": "nfsd: reset write verifier on deferred writeback errors",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-53393",
    "datePublished": "2026-07-19T12:01:56.684Z",
    "dateReserved": "2026-06-09T07:44:35.402Z",
    "dateUpdated": "2026-07-19T12:01:56.684Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-53393",
      "date": "2026-07-21",
      "epss": "0.00168",
      "percentile": "0.06439"
    },
    "microsoft_vex": {
      "current_release_date": "2026-07-20T14:43:45.000Z",
      "cve": "CVE-2026-53393",
      "id": "msrc_CVE-2026-53393",
      "initial_release_date": "2026-07-20T01:04:37.000Z",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "nfsd: reset write verifier on deferred writeback errors",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-53393.json",
      "version": "2"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-53393\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-19T12:16:50.367\",\"lastModified\":\"2026-07-19T12:16:50.367\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnfsd: reset write verifier on deferred writeback errors\\n\\nnfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to\\ndetect deferred writeback errors, but neither rotates the server\u0027s write\\nverifier (nn-\u003ewriteverf) when this check fails. Every other\\ndurable-storage-failure path in these functions calls\\ncommit_reset_write_verifier() before returning an error.\\n\\nThe missing rotation means clients holding UNSTABLE write data under the\\ncurrent verifier will COMMIT, receive the unchanged verifier back, and\\nconclude their data is durable \u2014 silently dropping data that failed\\nwriteback. This violates the UNSTABLE+COMMIT durability contract\\n(RFC 1813 \u00a73.3.7, RFC 8881 \u00a718.32).\\n\\nAdd commit_reset_write_verifier() calls at both filemap_check_wb_err()\\nerror sites, matching the pattern used by adjacent error paths in the\\nsame functions. The helper already filters -EAGAIN and -ESTALE\\ninternally, so the calls are unconditionally safe.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/nfsd/vfs.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"555dbf1a9aac6d3150c8b52fa35f768a692f4eeb\",\"lessThan\":\"1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"555dbf1a9aac6d3150c8b52fa35f768a692f4eeb\",\"lessThan\":\"4367afc119c51e17a616f6908772b7e2c2c4013f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"555dbf1a9aac6d3150c8b52fa35f768a692f4eeb\",\"lessThan\":\"b027cca33c97354149fcc0ddeede4525c41093cd\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"555dbf1a9aac6d3150c8b52fa35f768a692f4eeb\",\"lessThan\":\"2090b05803faab8a9fa62fbff871007862cac1b7\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f14816f2f928c560d28ba344af689f56efcd6f55\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3145fe0ebb16e1715ad541a301bc6675c8375fcd\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"5.10.124\",\"lessThan\":\"5.11\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"5.15.49\",\"lessThan\":\"5.16\",\"versionType\":\"semver\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/nfsd/vfs.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.17\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.17\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.95\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.38\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.3\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2090b05803faab8a9fa62fbff871007862cac1b7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4367afc119c51e17a616f6908772b7e2c2c4013f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b027cca33c97354149fcc0ddeede4525c41093cd\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-20T14:19:11+00:00",
      "cve": "CVE-2026-53393",
      "id": "CVE-2026-53393",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_affected": "198",
      "product_status:known_not_affected": "77",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: nfsd: reset write verifier on deferred writeback errors",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53393.json",
      "version": "3"
    }
  }
}



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.