CVE-2026-31535

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: make use of smbdirect_socket.recv_io.credits.available The logic off managing recv credits by counting posted recv_io and granted credits is racy. That's because the peer might already consumed a credit, but between receiving the incoming recv at the hardware and processing the completion in the 'recv_done' functions we likely have a window where we grant credits, which don't really exist. So we better have a decicated counter for the available credits, which will be incremented when we posted new recv buffers and drained when we grant the credits to the peer.

Severity

MEDIUM

CVSS score

4.7 (v3.1)

Vulnerability status

Analyzed

Source identifier

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

Published

2026-04-24 15:16:27.427000

Last modified

2026-11-05 22:18:39.043000

View original CVE JSON

{
  "id": "CVE-2026-31535",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-04-24T15:16:27.427",
  "lastModified": "2026-11-05T22:18:39.043",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: make use of smbdirect_socket.recv_io.credits.available\n\nThe logic off managing recv credits by counting posted recv_io and\ngranted credits is racy.\n\nThat's because the peer might already consumed a credit,\nbut between receiving the incoming recv at the hardware\nand processing the completion in the 'recv_done' functions\nwe likely have a window where we grant credits, which\ndon't really exist.\n\nSo we better have a decicated counter for the\navailable credits, which will be incremented\nwhen we posted new recv buffers and drained when\nwe grant the credits to the peer."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/smb/client/smbdirect.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5fb9b459b3686e366640edd4e62805ef7b4de927",
              "lessThan": "f664e6e8a81103cb45c8802a9bc7499e0902c458",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5fb9b459b3686e366640edd4e62805ef7b4de927",
              "lessThan": "be8845ad5d6558703d20567d8702155598325db8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5fb9b459b3686e366640edd4e62805ef7b4de927",
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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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              "status": "affected"
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              "version": "0",
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              "versionType": "semver",
              "status": "unaffected"
            },
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              "version": "6.18.11",
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              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.19.1",
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              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.0",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 4.7,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "HIGH",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.0,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-11-05T21:37:58.578551Z",
          "id": "CVE-2026-31535",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
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  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-367"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.18",
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  "references": [
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}