{"id":"CVE-2026-90074","revision":"69aed0424acc4bb59918bcbf02802412","records":[{"revision":"69aed0424acc4bb59918bcbf02802412","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-90074","aliases":[],"title":"net/sched: fq_pie: clamp default quantum to avoid signed overflow","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fq_pie: clamp default quantum to avoid signed overflow\n\nfq_pie_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) without\nclamping. A device with a huge MTU (e.g. dummy with max_mtu == 0\naccepting MTU 2147483634) makes psched_mtu() return 0x80000000, which\noverflows the signed flow->deficit to INT_MIN in fq_pie_qdisc_dequeue(),\ncausing an infinite loop and soft lockup. Emulate fq_pie_policy which\nis already bounded to [1, 1 << 20]; clamp the default to [256, 1 << 20].\n256 matches fq_codel's floor and is a sane minimum for a DRR quantum.\n\nConditions to recreate the bug: a device whose MTU (plus\nhard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy\ndevice with max_mtu == 0 accepting MTU 2147483634). Requires\nCAP_NET_ADMIN in a user namespace.","state":0,"publishedAt":"2026-09-17T16:05:54.214+00:00","modifiedAt":"2026-10-19T08:57:31.165+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/sched/sch_fq_pie.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a\",\n                            \"lessThan\": \"1f43e4dbc93b7d02761a024d5f895df823c07b72\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a\",\n                            \"lessThan\": \"f7942b2693bc24c7d609a03d06f97bee3b0bd96a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a\",\n                            \"lessThan\": \"6f1be05faecef4c0f9a008200209f66ef2e133f7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a\",\n                            \"lessThan\": \"435da3734a8e63d3067016accc977ed1d10aaaa0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a\",\n                            \"lessThan\": \"44dad8fe99b58a7fe2961e9eec6a5f07ace5b51f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a\",\n                            \"lessThan\": \"044fa2498bbc2900f0c48a6ef2fdd5b2bdfc3795\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a\",\n                            \"lessThan\": \"bf97fd2163ad1191ef8daa3d4df8372aee19e396\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a\",\n                            \"lessThan\": \"c86cd7ed0b0e44779a3d1683f03e4353baf4bdc9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/sched/sch_fq_pie.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.6\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.6\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.270\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.221\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.188\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.157\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.52\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.6\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/1f43e4dbc93b7d02761a024d5f895df823c07b72","https://git.kernel.org/stable/c/f7942b2693bc24c7d609a03d06f97bee3b0bd96a","https://git.kernel.org/stable/c/6f1be05faecef4c0f9a008200209f66ef2e133f7","https://git.kernel.org/stable/c/435da3734a8e63d3067016accc977ed1d10aaaa0","https://git.kernel.org/stable/c/44dad8fe99b58a7fe2961e9eec6a5f07ace5b51f","https://git.kernel.org/stable/c/044fa2498bbc2900f0c48a6ef2fdd5b2bdfc3795","https://git.kernel.org/stable/c/bf97fd2163ad1191ef8daa3d4df8372aee19e396","https://git.kernel.org/stable/c/c86cd7ed0b0e44779a3d1683f03e4353baf4bdc9"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-90074","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-90074","identifiers":["CVE-2026-90074"]},"retained":false,"historicalAffected":[]}],"coverage":[]}