{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "20f6a05ef63594feb0c6dfbd629da0448b43124d"
            },
            {
              "fixed": "630a15a31c2034b5b697f4aabc769b9d80d82446"
            },
            {
              "fixed": "e8ec80430bfa520e7352155d6ac632e527cba7aa"
            },
            {
              "fixed": "c9bc352f716d1bebfe43354bce539ec2d0223b30"
            },
            {
              "fixed": "fa6e24963342de4370e3a3c9af41e38277b74cf3"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.8.0"
            },
            {
              "fixed": "6.12.92"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.34"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31420.json"
  },
  "details": "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",
  "modified": "2026-07-08T05:36:18.158646462Z",
  "published": "2026-04-13T13:40:24.594Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/630a15a31c2034b5b697f4aabc769b9d80d82446"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c9bc352f716d1bebfe43354bce539ec2d0223b30"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e8ec80430bfa520e7352155d6ac632e527cba7aa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fa6e24963342de4370e3a3c9af41e38277b74cf3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31420.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31420"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "bridge: mrp: reject zero test interval to avoid OOM panic"
}