CVE-2026-98124 (GCVE-0-2026-98124)
Vulnerability from cvelistv5
Published
2026-09-25 10:36
Modified
2026-10-21 12:54
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: smb/client: invalidate fscache for fallocate range operations smb3_zero_range(), smb3_punch_hole(), smb3_insert_range(), and smb3_collapse_range() modify file contents through server-side range operations. These operations discard the affected page cache, but leave the FS-Cache cookie valid, so a later read may return data cached before the range operation. Fix this by invalidating FS-Cache after outstanding I/O has completed and before modifying the file on the server. Run the following as root on a CIFS mount with fsc enabled and an active CacheFiles backend: bash -c ' MNT=/mnt/cifs FILE="$MNT/repro" # Generate four 1 MiB random blocks: [A][B][C][D]. dd if=/dev/urandom of=/tmp/src bs=1M count=4 status=none # Expected contents after zeroing B: [A][zero][C][D]. cp /tmp/src /tmp/expected dd if=/dev/zero of=/tmp/expected bs=1M seek=1 count=1 \ conv=notrunc status=none cp /tmp/src "$FILE" # Populate FS-Cache, then discard the page cache. sync echo 1 > /proc/sys/vm/drop_caches cat "$FILE" > /dev/null sync echo 1 > /proc/sys/vm/drop_caches fallocate --zero-range -o 1M -l 1M "$FILE" if cmp -s /tmp/expected "$FILE"; then echo "readback: OK" else echo "readback: STALE DATA" fi ' Before this change, the readback differs from /tmp/expected: readback: STALE DATA After this change, it matches: readback: OK
References
Impacted products
Vendor Product Version
Linux Linux Version: 31742c5a331766bc7df6b0d525df00c6cd20d5a6
Version: 31742c5a331766bc7df6b0d525df00c6cd20d5a6
Version: 31742c5a331766bc7df6b0d525df00c6cd20d5a6
Version: 31742c5a331766bc7df6b0d525df00c6cd20d5a6
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "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": "cc7202a51b8777a757bda9dcfbf339f828c6a130",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "dd8b1e808f5c19479e6ed47e2f88a1fd46f8b0e5",
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            },
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              "versionType": "git"
            },
            {
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              "status": "affected",
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              "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": "3.17"
            },
            {
              "lessThan": "3.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.160",
                  "versionStartIncluding": "3.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.114",
                  "versionStartIncluding": "3.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.7",
                  "versionStartIncluding": "3.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "3.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb/client: invalidate fscache for fallocate range operations\n\nsmb3_zero_range(), smb3_punch_hole(), smb3_insert_range(), and\nsmb3_collapse_range() modify file contents through server-side range\noperations. These operations discard the affected page cache, but leave\nthe FS-Cache cookie valid, so a later read may return data cached before\nthe range operation.\n\nFix this by invalidating FS-Cache after outstanding I/O has completed\nand before modifying the file on the server.\n\nRun the following as root on a CIFS mount with fsc enabled and an active\nCacheFiles backend:\n\n        bash -c \u0027\n                MNT=/mnt/cifs\n                FILE=\"$MNT/repro\"\n\n                # Generate four 1 MiB random blocks: [A][B][C][D].\n                dd if=/dev/urandom of=/tmp/src bs=1M count=4 status=none\n\n                # Expected contents after zeroing B: [A][zero][C][D].\n                cp /tmp/src /tmp/expected\n                dd if=/dev/zero of=/tmp/expected bs=1M seek=1 count=1 \\\n                        conv=notrunc status=none\n                cp /tmp/src \"$FILE\"\n\n                # Populate FS-Cache, then discard the page cache.\n                sync\n                echo 1 \u003e /proc/sys/vm/drop_caches\n                cat \"$FILE\" \u003e /dev/null\n                sync\n                echo 1 \u003e /proc/sys/vm/drop_caches\n\n                fallocate --zero-range -o 1M -l 1M \"$FILE\"\n\n                if cmp -s /tmp/expected \"$FILE\"; then\n                        echo \"readback: OK\"\n                else\n                        echo \"readback: STALE DATA\"\n                fi\n        \u0027\n\nBefore this change, the readback differs from /tmp/expected:\n\n        readback: STALE DATA\n\nAfter this change, it matches:\n\n        readback: OK"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:54:35.267Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/cc7202a51b8777a757bda9dcfbf339f828c6a130"
        },
        {
          "url": "https://git.kernel.org/stable/c/dd8b1e808f5c19479e6ed47e2f88a1fd46f8b0e5"
        },
        {
          "url": "https://git.kernel.org/stable/c/93c6e5a8d7c5071d586c1411596d5db5faad22b2"
        },
        {
          "url": "https://git.kernel.org/stable/c/448ba0ae65ca61064183564d2983c9aa59bd6ba7"
        }
      ],
      "title": "smb/client: invalidate fscache for fallocate range operations",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98124",
    "datePublished": "2026-09-25T10:36:06.581Z",
    "dateReserved": "2026-09-25T10:25:14.318Z",
    "dateUpdated": "2026-10-21T12:54:35.267Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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