CVE-2026-31420 (GCVE-0-2026-31420)

Vulnerability from cvelistv5 – Published: 2026-04-13 13:40 – Updated: 2026-06-01 16:11
VLAI?
Title
bridge: mrp: reject zero test interval to avoid OOM panic
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.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 20f6a05ef63594feb0c6dfbd629da0448b43124d , < 630a15a31c2034b5b697f4aabc769b9d80d82446 (git)
Affected: 20f6a05ef63594feb0c6dfbd629da0448b43124d , < e8ec80430bfa520e7352155d6ac632e527cba7aa (git)
Affected: 20f6a05ef63594feb0c6dfbd629da0448b43124d , < c9bc352f716d1bebfe43354bce539ec2d0223b30 (git)
Affected: 20f6a05ef63594feb0c6dfbd629da0448b43124d , < fa6e24963342de4370e3a3c9af41e38277b74cf3 (git)
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    Linux Linux Affected: 5.8
Unaffected: 0 , < 5.8 (semver)
Unaffected: 6.12.92 , ≤ 6.12.* (semver)
Unaffected: 6.18.34 , ≤ 6.18.* (semver)
Unaffected: 6.19.12 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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          "programFiles": [
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      "descriptions": [
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          "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-01T16:11:26.083Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
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    "cveId": "CVE-2026-31420",
    "datePublished": "2026-04-13T13:40:24.594Z",
    "dateReserved": "2026-03-09T15:48:24.088Z",
    "dateUpdated": "2026-06-01T16:11:26.083Z",
    "state": "PUBLISHED"
  },
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}


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