{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/netfs/direct_write.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a4d1b4ba9754bac3efebd06f583a44a7af52c0ab",
              "status": "affected",
              "version": "72d08d2839649d1c5efbe375751f4473fa4486af",
              "versionType": "git"
            },
            {
              "lessThan": "7a5482f5ce891decbf36f2e6fab1e9fc4a76a684",
              "status": "affected",
              "version": "0c29f6d63122a0168d67cb8ecde5b4cf7fe4acb0",
              "versionType": "git"
            },
            {
              "lessThan": "e9075e420a1eb3b52c60f3b95893a55e77419ce8",
              "status": "affected",
              "version": "a0b4c7a49137ed21279f354eb59f49ddae8dffc2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/netfs/direct_write.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6.18.21",
              "status": "affected",
              "version": "6.18.17",
              "versionType": "semver"
            },
            {
              "lessThan": "6.19.11",
              "status": "affected",
              "version": "6.19.7",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.21",
                  "versionStartIncluding": "6.18.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.11",
                  "versionStartIncluding": "6.19.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix NULL pointer dereference in netfs_unbuffered_write() on retry\n\nWhen a write subrequest is marked NETFS_SREQ_NEED_RETRY, the retry path\nin netfs_unbuffered_write() unconditionally calls stream-\u003eprepare_write()\nwithout checking if it is NULL.\n\nFilesystems such as 9P do not set the prepare_write operation, so\nstream-\u003eprepare_write remains NULL. When get_user_pages() fails with\n-EFAULT and the subrequest is flagged for retry, this results in a NULL\npointer dereference at fs/netfs/direct_write.c:189.\n\nFix this by mirroring the pattern already used in write_retry.c: if\nstream-\u003eprepare_write is NULL, skip renegotiation and directly reissue\nthe subrequest via netfs_reissue_write(), which handles iterator reset,\nIN_PROGRESS flag, stats update and reissue internally."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-22T13:53:36.361Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/a4d1b4ba9754bac3efebd06f583a44a7af52c0ab"
        },
        {
          "url": "https://git.kernel.org/stable/c/7a5482f5ce891decbf36f2e6fab1e9fc4a76a684"
        },
        {
          "url": "https://git.kernel.org/stable/c/e9075e420a1eb3b52c60f3b95893a55e77419ce8"
        }
      ],
      "title": "netfs: Fix NULL pointer dereference in netfs_unbuffered_write() on retry",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31437",
    "datePublished": "2026-04-22T13:53:36.361Z",
    "dateReserved": "2026-03-09T15:48:24.090Z",
    "dateUpdated": "2026-04-22T13:53:36.361Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-31437",
      "date": "2026-04-23",
      "epss": "0.00017",
      "percentile": "0.04046"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-31437\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-04-22T14:16:36.980\",\"lastModified\":\"2026-04-23T16:17:41.280\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnetfs: Fix NULL pointer dereference in netfs_unbuffered_write() on retry\\n\\nWhen a write subrequest is marked NETFS_SREQ_NEED_RETRY, the retry path\\nin netfs_unbuffered_write() unconditionally calls stream-\u003eprepare_write()\\nwithout checking if it is NULL.\\n\\nFilesystems such as 9P do not set the prepare_write operation, so\\nstream-\u003eprepare_write remains NULL. When get_user_pages() fails with\\n-EFAULT and the subrequest is flagged for retry, this results in a NULL\\npointer dereference at fs/netfs/direct_write.c:189.\\n\\nFix this by mirroring the pattern already used in write_retry.c: if\\nstream-\u003eprepare_write is NULL, skip renegotiation and directly reissue\\nthe subrequest via netfs_reissue_write(), which handles iterator reset,\\nIN_PROGRESS flag, stats update and reissue internally.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/7a5482f5ce891decbf36f2e6fab1e9fc4a76a684\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a4d1b4ba9754bac3efebd06f583a44a7af52c0ab\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/e9075e420a1eb3b52c60f3b95893a55e77419ce8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}