cifs: don't update i_size in cifs_do_truncate without a cached handle

{
  "id": "445634ab45009e8b4233ed08be3afeb1820654476117b01fa2d8a9da06e05b3f",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-99137",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "cifs: don't update i_size in cifs_do_truncate without a cached handle",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: cifs: don't update i_size in cifs_do_truncate without a cached handle If find_writable_file() returns null, cifs_file_flush will return 0 without issuing set_file_size, and the outer 'if (!rc)' block will set i_size to 0 before telling the server to truncate. If the cifs_open() then fails, the inode will have size 0, while the server file is unchanged. Move the netfs_resize_file() and cifs_setsize() into the 'if (cfile)', so they only run after a successful set_file_size. In the no-handle else branch, evict stale pages with truncate_inode_pages before the O_TRUNC open to dispose of old cache pages, and let the open response set the i_size.",
    "evidence": "cve:CVE-2026-99137",
    "products": [
      {
        "name": {
          "value": "Linux",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      },
      {
        "name": {
          "value": "Linux",
          "evidence": "/containers/cna/affected/1/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-99137",
      "aliases": [
        "CVE-2026-99137"
      ],
      "metrics": [],
      "affected": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "110fee6b9bb58a5c50047fc2594d415f741b591e",
              "lessThan": "04d020b3d0b58a1b7e116900e4095b96a7f4e11a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "110fee6b9bb58a5c50047fc2594d415f741b591e",
              "lessThan": "88a51743cd8094b76fd910f53f718747c7729cc8",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "110fee6b9bb58a5c50047fc2594d415f741b591e",
              "lessThan": "fe39cd9d48f2346605f3746e0cc19e89d5f373eb",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/smb/client/file.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.18"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.18",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.59",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.13",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/smb/client/file.c"
          ],
          "defaultStatus": "affected"
        }
      ],
      "modified": "2026-10-28T10:34:49.266Z",
      "provider": "cve",
      "references": [
        "https://git.kernel.org/stable/c/04d020b3d0b58a1b7e116900e4095b96a7f4e11a",
        "https://git.kernel.org/stable/c/88a51743cd8094b76fd910f53f718747c7729cc8",
        "https://git.kernel.org/stable/c/fe39cd9d48f2346605f3746e0cc19e89d5f373eb"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
          "shortName": "Linux",
          "dateUpdated": "2026-10-28T10:34:49.266Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-99137",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-cve",
  "document_id": 425353,
  "published_at": "2026-10-28T10:34:49.266+00:00"
}