FKIE_CVE-2026-98126

Vulnerability from fkie_nvd - Published: 2026-09-25 11:17 - Updated: 2026-09-25 11:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: smb/client: validate new EOF for zero range When FALLOC_FL_ZERO_RANGE is used without FALLOC_FL_KEEP_SIZE, smb3_zero_range() may extend EOF without checking RLIMIT_FSIZE, allowing the file to grow beyond the caller's file-size limit. Fix this by calling inode_newsize_ok() before sending the zero-range request when the operation would extend EOF. Reproducer, using a file on a CIFS mount: bash -c ' FILE=/mnt/cifs/repro trap "" SIGXFSZ ulimit -f 3072 truncate -s 2M "$FILE" fallocate --zero-range -o 0 -l 4M "$FILE" echo "fallocate rc=$?" stat -c "file size=%s" "$FILE" ' Before this change, the operation succeeds despite the 3 MiB limit: fallocate rc=0 file size=4194304 After this change, fallocate fails and leaves the file at 2 MiB.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/06a4f9049cb6dc319bceec2dc813ba89add8b828
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3673f057b64abfa957e8ae84448db69369a5091a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/88972e35750792e717af287dc71f42a03b5cbce4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f320ca20c273a26cd779bdb2b2e4b076a95c76f6
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/smb2ops.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3673f057b64abfa957e8ae84448db69369a5091a",
              "status": "affected",
              "version": "72c419d9b073628d3b5b0b2fc787b724f1a8c726",
              "versionType": "git"
            },
            {
              "lessThan": "06a4f9049cb6dc319bceec2dc813ba89add8b828",
              "status": "affected",
              "version": "72c419d9b073628d3b5b0b2fc787b724f1a8c726",
              "versionType": "git"
            },
            {
              "lessThan": "f320ca20c273a26cd779bdb2b2e4b076a95c76f6",
              "status": "affected",
              "version": "72c419d9b073628d3b5b0b2fc787b724f1a8c726",
              "versionType": "git"
            },
            {
              "lessThan": "88972e35750792e717af287dc71f42a03b5cbce4",
              "status": "affected",
              "version": "72c419d9b073628d3b5b0b2fc787b724f1a8c726",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/smb2ops.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.1"
            },
            {
              "lessThan": "5.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc2",
              "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\nsmb/client: validate new EOF for zero range\n\nWhen FALLOC_FL_ZERO_RANGE is used without FALLOC_FL_KEEP_SIZE,\nsmb3_zero_range() may extend EOF without checking RLIMIT_FSIZE, allowing\nthe file to grow beyond the caller\u0027s file-size limit.\n\nFix this by calling inode_newsize_ok() before sending the zero-range\nrequest when the operation would extend EOF.\n\nReproducer, using a file on a CIFS mount:\n\n\tbash -c \u0027\n\t        FILE=/mnt/cifs/repro\n\n\t        trap \"\" SIGXFSZ\n\t        ulimit -f 3072\n\n\t        truncate -s 2M \"$FILE\"\n\t        fallocate --zero-range -o 0 -l 4M \"$FILE\"\n\t        echo \"fallocate rc=$?\"\n\t        stat -c \"file size=%s\" \"$FILE\"\n\t\u0027\n\nBefore this change, the operation succeeds despite the 3 MiB limit:\n\n\tfallocate rc=0\n\tfile size=4194304\n\nAfter this change, fallocate fails and leaves the file at 2 MiB."
    }
  ],
  "id": "CVE-2026-98126",
  "lastModified": "2026-09-25T11:17:43.940",
  "metrics": {},
  "published": "2026-09-25T11:17:43.940",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/06a4f9049cb6dc319bceec2dc813ba89add8b828"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3673f057b64abfa957e8ae84448db69369a5091a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/88972e35750792e717af287dc71f42a03b5cbce4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f320ca20c273a26cd779bdb2b2e4b076a95c76f6"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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