CVE-2026-31420

bridge: mrp: reject zero test interval to avoid OOM panic

cve-program · severity unknownCVSS unknownCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-31420

Published

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.

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-31420

Published

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/bridge/br_mrp_netlink.c"
                    ],
                    "versions": [
                        {
                            "version": "20f6a05ef63594feb0c6dfbd629da0448b43124d",
                            "lessThan": "610073ffb77ffd2b5eca182d2ac264de4834a175",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "20f6a05ef63594feb0c6dfbd629da0448b43124d",
                            "lessThan": "ec8850be9b2b3beac1c7967d95f169dd2785979d",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "20f6a05ef63594feb0c6dfbd629da0448b43124d",
                            "lessThan": "1ec86b4b9e28170a2565cf36f0e6e2b96b55134d",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "20f6a05ef63594feb0c6dfbd629da0448b43124d",
                            "lessThan": "2120bd8546cd6a63c558d135773aa8f41c8259fc",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "20f6a05ef63594feb0c6dfbd629da0448b43124d",
                            "lessThan": "630a15a31c2034b5b697f4aabc769b9d80d82446",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "20f6a05ef63594feb0c6dfbd629da0448b43124d",
                            "lessThan": "e8ec80430bfa520e7352155d6ac632e527cba7aa",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "20f6a05ef63594feb0c6dfbd629da0448b43124d",
                            "lessThan": "c9bc352f716d1bebfe43354bce539ec2d0223b30",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "20f6a05ef63594feb0c6dfbd629da0448b43124d",
                            "lessThan": "fa6e24963342de4370e3a3c9af41e38277b74cf3",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                }

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/bridge/br_mrp_netlink.c"
                    ],
                    "versions": [
                        {
                            "version": "5.8",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.8",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.270",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.221",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.188",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.157",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.92",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.34",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19.12",
                            "lessThanOrEqual": "6.19.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON