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

Vulnerability from cvelistv5 – Published: 2026-04-13 13:40 – Updated: 2026-05-11 22:08
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 , < c9bc352f716d1bebfe43354bce539ec2d0223b30 (git)
Affected: 20f6a05ef63594feb0c6dfbd629da0448b43124d , < fa6e24963342de4370e3a3c9af41e38277b74cf3 (git)
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Linux Linux Affected: 5.8
Unaffected: 0 , < 5.8 (semver)
Unaffected: 6.19.12 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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