CVE-2026-98479

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi_tcp: Check the data direction of a Data-In PDU The Data-In branch of iscsi_tcp_hdr_dissect() resolves the ITT to a task and copies the PDU's data segment into that command's scatterlist without asking whether the command was reading. iscsi_tcp_r2t_rsp() in the same file does ask, and rejects an R2T for a command that is not DMA_TO_DEVICE. A target that answers a WRITE command's ITT with a Data-In therefore has the initiator write target-supplied bytes into the pages that write was about to send. Those are the caller's own pinned pages for an O_DIRECT write, and page cache pages for a buffered one. Observed against a test target that emits one 512-byte Data-In naming a 128 KB write's ITT, after the R2T for that write. With O_DIRECT the caller's buffer ends up holding 512 bytes of the target's data while pwrite() returns 131072. Buffered is quieter: pwrite() and fsync() both succeed, nothing is logged, and reading those blocks back returns the target's bytes out of the page cache without a command going on the wire. Check the direction before using the scatterlist, the way the R2T path already does.

Severity

HIGH

CVSS score

7.5 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-18 16:16:58.467000

Last modified

2026-10-24 14:16:43.610000

View original CVE JSON

{
  "id": "CVE-2026-98479",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:16:58.467",
  "lastModified": "2026-10-24T14:16:43.610",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libiscsi_tcp: Check the data direction of a Data-In PDU\n\nThe Data-In branch of iscsi_tcp_hdr_dissect() resolves the ITT to a task\nand copies the PDU's data segment into that command's scatterlist without\nasking whether the command was reading. iscsi_tcp_r2t_rsp() in the same\nfile does ask, and rejects an R2T for a command that is not DMA_TO_DEVICE.\n\nA target that answers a WRITE command's ITT with a Data-In therefore has\nthe initiator write target-supplied bytes into the pages that write was\nabout to send. Those are the caller's own pinned pages for an O_DIRECT\nwrite, and page cache pages for a buffered one.\n\nObserved against a test target that emits one 512-byte Data-In naming a 128\nKB write's ITT, after the R2T for that write. With O_DIRECT the caller's\nbuffer ends up holding 512 bytes of the target's data while pwrite()\nreturns 131072. Buffered is quieter: pwrite() and fsync() both succeed,\nnothing is logged, and reading those blocks back returns the target's bytes\nout of the page cache without a command going on the wire.\n\nCheck the direction before using the scatterlist, the way the R2T path\nalready does."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/scsi/libiscsi_tcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "a081c13e39b5c17052a7b46fafa61019c4c110ff",
              "lessThan": "79991b770fc3685b1d5cf805b659a879edd19931",
              "versionType": "git",
              "status": "affected"
            },
            {
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              "lessThan": "8db1232945bc663fb94f300090a1fc108de99296",
              "versionType": "git",
              "status": "affected"
            },
            {
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              "versionType": "git",
              "status": "affected"
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              "versionType": "git",
              "status": "affected"
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              "versionType": "git",
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              "versionType": "git",
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              "versionType": "git",
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        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/scsi/libiscsi_tcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "2.6.29",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "2.6.29",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.271",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.222",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.189",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.55",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.9",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/24ffc919467d20951f0f132d1c75294e2e91e09b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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}