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CVE-2026-98126

Full vulnerability record from the local CVENow database.

Description

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.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-25 11:17:43.940000
Last modified
2026-10-22 16:02:09.817000
View original CVE JSON 
{
  "id": "CVE-2026-98126",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:43.940",
  "lastModified": "2026-10-22T16:02:09.817",
  "vulnStatus": "Analyzed",
  "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's 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 '\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'\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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
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          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
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          "programFiles": [
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
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            },
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              "version": "7.2.7",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
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          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ]
    }
  ],
  "configurations": [
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          "negate": false,
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}