GHSA-644J-VC34-VF98
Vulnerability from github – Published: 2026-04-13 15:31 – Updated: 2026-04-13 15:31In 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.
{
"affected": [],
"aliases": [
"CVE-2026-31420"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-13T14:16:11Z",
"severity": null
},
"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": "GHSA-644j-vc34-vf98",
"modified": "2026-04-13T15:31:42Z",
"published": "2026-04-13T15:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31420"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c9bc352f716d1bebfe43354bce539ec2d0223b30"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fa6e24963342de4370e3a3c9af41e38277b74cf3"
}
],
"schema_version": "1.4.0",
"severity": []
}
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