FKIE_CVE-2026-31420

Vulnerability from fkie_nvd - Published: 2026-04-13 14:16 - Updated: 2026-06-17 10:33
Severity
5.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: bridge: mrp: reject zero test interval to avoid OOM panic br_mrp_start_test() and br_mrp_start_in_test() accept the user-supplied interval value from netlink without validation. When interval is 0, usecs_to_jiffies(0) yields 0, causing the delayed work (br_mrp_test_work_expired / br_mrp_in_test_work_expired) to reschedule itself with zero delay. This creates a tight loop on system_percpu_wq that allocates and transmits MRP test frames at maximum rate, exhausting all system memory and causing a kernel panic via OOM deadlock. The same zero-interval issue applies to br_mrp_start_in_test_parse() for interconnect test frames. Use NLA_POLICY_MIN(NLA_U32, 1) in the nla_policy tables for both IFLA_BRIDGE_MRP_START_TEST_INTERVAL and IFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL, so zero is rejected at the netlink attribute parsing layer before the value ever reaches the workqueue scheduling code. This is consistent with how other bridge subsystems (br_fdb, br_mst) enforce range constraints on netlink attributes.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/630a15a31c2034b5b697f4aabc769b9d80d82446
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c9bc352f716d1bebfe43354bce539ec2d0223b30Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e8ec80430bfa520e7352155d6ac632e527cba7aa
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fa6e24963342de4370e3a3c9af41e38277b74cf3Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bridge/br_mrp_netlink.c"
          ],
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          "vendor": "Linux",
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.8"
            },
            {
              "lessThan": "5.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
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  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbridge: mrp: reject zero test interval to avoid OOM panic\n\nbr_mrp_start_test() and br_mrp_start_in_test() accept the user-supplied\ninterval value from netlink without validation. When interval is 0,\nusecs_to_jiffies(0) yields 0, causing the delayed work\n(br_mrp_test_work_expired / br_mrp_in_test_work_expired) to reschedule\nitself with zero delay. This creates a tight loop on system_percpu_wq\nthat allocates and transmits MRP test frames at maximum rate, exhausting\nall system memory and causing a kernel panic via OOM deadlock.\n\nThe same zero-interval issue applies to br_mrp_start_in_test_parse()\nfor interconnect test frames.\n\nUse NLA_POLICY_MIN(NLA_U32, 1) in the nla_policy tables for both\nIFLA_BRIDGE_MRP_START_TEST_INTERVAL and\nIFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL, so zero is rejected at the\nnetlink attribute parsing layer before the value ever reaches the\nworkqueue scheduling code. This is consistent with how other bridge\nsubsystems (br_fdb, br_mst) enforce range constraints on netlink\nattributes."
    }
  ],
  "id": "CVE-2026-31420",
  "lastModified": "2026-06-17T10:33:40.980",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-04-13T14:16:11.617",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/630a15a31c2034b5b697f4aabc769b9d80d82446"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
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      "url": "https://git.kernel.org/stable/c/c9bc352f716d1bebfe43354bce539ec2d0223b30"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e8ec80430bfa520e7352155d6ac632e527cba7aa"
    },
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      "url": "https://git.kernel.org/stable/c/fa6e24963342de4370e3a3c9af41e38277b74cf3"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-667"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}


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