CVE-2026-90076

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-90076", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.785Z", "datePublished": "2026-09-17T16:05:55.517Z", "dateUpdated": "2026-10-30T12:34:01.376Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:34:01.376Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fq: add overflow bounds to quantum and initial quantum\n\nfq_init() computes quantum = 2 * psched_mtu() and initial_quantum = 10 *\npsched_mtu() with no overflow check. A device with a huge MTU (e.g. dummy\nwith max_mtu == 0 accepting MTU 2147483634) makes psched_mtu() return\n0x80000000; the 2 * and 10 * multiplications wrap to 0 in 32-bit\narithmetic, so q->quantum == 0. Then in fq_dequeue() the credit-refill\nloop adds 0 to f->credit (which stays <= 0) and goto begin loops\nforever under the qdisc lock, creating a soft lockup.\n\nClamp psched_mtu() to [1, 1 << 20] before multiplying so the product\ncannot wrap, then cap the result at 1 << 20, matching the bound already\nenforced on TCA_FQ_QUANTUM in fq_change().\n\nConditions to recreate the bug: a device whose MTU (plus\nhard_header_len) is large enough that 2 * psched_mtu() wraps (e.g. a\ndummy device 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.c"], "versions": [{"version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "lessThan": "cf398f67d9caa71af3b9fb9319058b22fe6b524e", "status": "affected", "versionType": "git"}, {"version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "lessThan": "fd63409b669f9951f1cc6b02486a5254103800d1", "status": "affected", "versionType": "git"}, {"version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "lessThan": "d16dac3925be95ad46e986d4b139c9898b6e227f", "status": "affected", "versionType": "git"}, {"version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "lessThan": "f6b3e3848a5fca63438984acd6d9eceac80814c1", "status": "affected", "versionType": "git"}, {"version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "lessThan": "e35acd56f244d94355f9ab237c2ecc8fba5e6f04", "status": "affected", "versionType": "git"}, {"version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "lessThan": "709f34f7c28dc4dd6c40343d101850f11e172312", "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.c"], "versions": [{"version": "3.12", "status": "affected"}, {"version": "0", "lessThan": "3.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "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": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.12", "versionEndExcluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.12", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.12", "versionEndExcluding": "6.12.110"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.12", "versionEndExcluding": "6.18.52"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.12", "versionEndExcluding": "7.2.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.12", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/cf398f67d9caa71af3b9fb9319058b22fe6b524e"}, {"url": "https://git.kernel.org/stable/c/fd63409b669f9951f1cc6b02486a5254103800d1"}, {"url": "https://git.kernel.org/stable/c/d16dac3925be95ad46e986d4b139c9898b6e227f"}, {"url": "https://git.kernel.org/stable/c/f6b3e3848a5fca63438984acd6d9eceac80814c1"}, {"url": "https://git.kernel.org/stable/c/e35acd56f244d94355f9ab237c2ecc8fba5e6f04"}, {"url": "https://git.kernel.org/stable/c/709f34f7c28dc4dd6c40343d101850f11e172312"}], "title": "net/sched: fq: add overflow bounds to quantum and initial quantum", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/sched/sch_fq.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "cf398f67d9caa71af3b9fb9319058b22fe6b524e", "status": "affected", "version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "versionType": "git"}, {"lessThan": "fd63409b669f9951f1cc6b02486a5254103800d1", "status": "affected", "version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "versionType": "git"}, {"lessThan": "d16dac3925be95ad46e986d4b139c9898b6e227f", "status": "affected", "version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "versionType": "git"}, {"lessThan": "f6b3e3848a5fca63438984acd6d9eceac80814c1", "status": "affected", "version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "versionType": "git"}, {"lessThan": "e35acd56f244d94355f9ab237c2ecc8fba5e6f04", "status": "affected", "version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "versionType": "git"}, {"lessThan": "709f34f7c28dc4dd6c40343d101850f11e172312", "status": "affected", "version": "afe4fd062416b158a8a8538b23adc1930a9b88dc", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/sched/sch_fq.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "3.12"}, {"lessThan": "3.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.110", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.52", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fq: add overflow bounds to quantum and initial quantum\n\nfq_init() computes quantum = 2 * psched_mtu() and initial_quantum = 10 *\npsched_mtu() with no overflow check. A device with a huge MTU (e.g. dummy\nwith max_mtu == 0 accepting MTU 2147483634) makes psched_mtu() return\n0x80000000; the 2 * and 10 * multiplications wrap to 0 in 32-bit\narithmetic, so q->quantum == 0. Then in fq_dequeue() the credit-refill\nloop adds 0 to f->credit (which stays <= 0) and goto begin loops\nforever under the qdisc lock, creating a soft lockup.\n\nClamp psched_mtu() to [1, 1 << 20] before multiplying so the product\ncannot wrap, then cap the result at 1 << 20, matching the bound already\nenforced on TCA_FQ_QUANTUM in fq_change().\n\nConditions to recreate the bug: a device whose MTU (plus\nhard_header_len) is large enough that 2 * psched_mtu() wraps (e.g. a\ndummy device with max_mtu == 0 accepting MTU 2147483634). Requires\nCAP_NET_ADMIN in a user namespace."}], "id": "CVE-2026-90076", "lastModified": "2026-10-30T13:20:40.513", "metrics": {}, "published": "2026-09-17T17:16:56.820", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/709f34f7c28dc4dd6c40343d101850f11e172312"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cf398f67d9caa71af3b9fb9319058b22fe6b524e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d16dac3925be95ad46e986d4b139c9898b6e227f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e35acd56f244d94355f9ab237c2ecc8fba5e6f04"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f6b3e3848a5fca63438984acd6d9eceac80814c1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fd63409b669f9951f1cc6b02486a5254103800d1"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[afe4fd062416b158a8a8538b23adc1930a9b88dc,d16dac3925be95ad46e986d4b139c9898b6e227f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[afe4fd062416b158a8a8538b23adc1930a9b88dc,f6b3e3848a5fca63438984acd6d9eceac80814c1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[afe4fd062416b158a8a8538b23adc1930a9b88dc,e35acd56f244d94355f9ab237c2ecc8fba5e6f04)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[afe4fd062416b158a8a8538b23adc1930a9b88dc,709f34f7c28dc4dd6c40343d101850f11e172312)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "3.12"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,3.12)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.110,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.52,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.6,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-18T19:30:12.783833+00:00", "updated": "2026-09-20T04:00:09.698564+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-190"]}