{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-90075",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-11T19:38:34.785Z",
        "datePublished": "2026-09-17T16:05:54.851Z",
        "dateUpdated": "2026-10-19T08:57:32.110Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T08:57:32.110Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fq_codel: clamp default quantum and mtu\n\nfq_codel_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_codel_dequeue(),\ncausing an infinite loop and soft lockup. Emulate fq_codel_change()\nand constrain to [256, FQ_CODEL_QUANTUM_MAX].\n\nThe same unclamped psched_mtu() is assigned to q->cparams.mtu a bit\nbelow, and fq_codel_change() never updates it. codel_should_drop()\ntests \"*backlog <= params->mtu\"; with mtu == 0x80000000 (~2 GiB) and\nthe default 32 MiB memory_limit, the test is always true, so CoDel is\nsilently and completely disabled (no drops, no ECN). Declare a single\nclamped mtu and assign both q->quantum and q->cparams.mtu from it,\nwhich also removes the double psched_mtu() call.\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."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/sched/sch_fq_codel.c"
                    ],
                    "versions": [
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                            "version": "4b549a2ef4bef9965d97cbd992ba67930cd3e0fe",
                            "lessThan": "d315ee8a07fd1810880227319cf60e6cd925ef22",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4b549a2ef4bef9965d97cbd992ba67930cd3e0fe",
                            "lessThan": "a9a5b2943a00df2ab81a2209f31dd9e87016f120",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4b549a2ef4bef9965d97cbd992ba67930cd3e0fe",
                            "lessThan": "3782067ec0d485628b6f1f9ede3eeeb4f611fcf2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4b549a2ef4bef9965d97cbd992ba67930cd3e0fe",
                            "lessThan": "397e2b1f71d9f15b8b4e47d24eb620e4dff8878d",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4b549a2ef4bef9965d97cbd992ba67930cd3e0fe",
                            "lessThan": "324f86806673ae4a55f66d28db84577f46f615e1",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4b549a2ef4bef9965d97cbd992ba67930cd3e0fe",
                            "lessThan": "dfb4b61db886917244284b18b44b23d2254b82c2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4b549a2ef4bef9965d97cbd992ba67930cd3e0fe",
                            "lessThan": "9f499e5827fdb6d7fdb46a7ce731852f6b1a1bb9",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4b549a2ef4bef9965d97cbd992ba67930cd3e0fe",
                            "lessThan": "d9ebd8f9aa8b2773235889cb903fafd61f2d8585",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/sched/sch_fq_codel.c"
                    ],
                    "versions": [
                        {
                            "version": "3.5",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "3.5",
                            "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": "6.12.110",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.52",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.6",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "3.5",
                                    "versionEndExcluding": "5.10.270"
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                                {
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/d315ee8a07fd1810880227319cf60e6cd925ef22"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a9a5b2943a00df2ab81a2209f31dd9e87016f120"
                },
                {
                    "url": "https://git.kernel.org/stable/c/3782067ec0d485628b6f1f9ede3eeeb4f611fcf2"
                },
                {
                    "url": "https://git.kernel.org/stable/c/397e2b1f71d9f15b8b4e47d24eb620e4dff8878d"
                },
                {
                    "url": "https://git.kernel.org/stable/c/324f86806673ae4a55f66d28db84577f46f615e1"
                },
                {
                    "url": "https://git.kernel.org/stable/c/dfb4b61db886917244284b18b44b23d2254b82c2"
                },
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                    "url": "https://git.kernel.org/stable/c/9f499e5827fdb6d7fdb46a7ce731852f6b1a1bb9"
                },
                {
                    "url": "https://git.kernel.org/stable/c/d9ebd8f9aa8b2773235889cb903fafd61f2d8585"
                }
            ],
            "title": "net/sched: fq_codel: clamp default quantum and mtu",
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}