Answer in brief
CVE-2026-90072 records a Unknown severity vulnerability in net/sched: sfq: clamp quantum to avoid signed overflow soft lockup. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <86799499585af06a9431c9e7782658667bd62650 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2017c355a5a1af77736cd1739fe922f69b5652dc || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6581a82bf08ba5d4e2a6d4e3080df43315b296c4 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9d782c662879c3adaaca30e05c36910ad11b9e54 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d72dbdfaeb5b9b8d884e0e036c3442754379ef74 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <aeb8196ecb95146e3410f635628e6cd47352b3e5 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <da16c31517cd2c06bb2c78c73e91ae192c01c426 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <816e90057ab1879562a5b7cc688e35bb9027ae97 | 86799499585af06a9431c9e7782658667bd62650, 2017c355a5a1af77736cd1739fe922f69b5652dc, 6581a82bf08ba5d4e2a6d4e3080df43315b296c4, 9d782c662879c3adaaca30e05c36910ad11b9e54, d72dbdfaeb5b9b8d884e0e036c3442754379ef74, aeb8196ecb95146e3410f635628e6cd47352b3e5, da16c31517cd2c06bb2c78c73e91ae192c01c426, 816e90057ab1879562a5b7cc688e35bb9027ae97 |
| Linux/Linuxgeneric | 2.6.12 | Not reported |
Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 17, 2026
In the Linux kernel, the following vulnerability has been resolved: net/sched: sfq: clamp quantum to avoid signed overflow soft lockup sfq_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) (unsigned). A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes psched_mtu() return 0x80000000, so slot->allot = INT_MIN and INT_MIN + INT_MIN toggles between INT_MIN and 0 forever, spinning sfq_dequeue() under the qdisc lock. Clamp the quantum to [256, 1 << 20] so the refill loop terminates. The lower bound also covers q->quantum == 0 (psched_mtu() returning 0), which spins sfq_dequeue() identically. sfq_change() already rejects a negative quantum, so only the init path was exposed. Conditions to recreate the bug: a device whose MTU (plus hard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy device with max_mtu == 0 accepting MTU 2147483634). Requires CAP_NET_ADMIN in a user namespace.
Quoted source text, attributed separately from HOL analysis.