CVE-2026-90072net/sched: sfq: clamp quantum to avoid signed overflow soft lockup
- —Not scoredno CVSS score yet
- 0.22%Exploitation in 30 daysEPSS · top 88% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 32 days later
· 32 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.22% · top 88% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 86799499585af06a9431c9e7782658667bd62650
- affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 2017c355a5a1af77736cd1739fe922f69b5652dc
- affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 6581a82bf08ba5d4e2a6d4e3080df43315b296c4
- affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 9d782c662879c3adaaca30e05c36910ad11b9e54
- affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < d72dbdfaeb5b9b8d884e0e036c3442754379ef74
- affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < aeb8196ecb95146e3410f635628e6cd47352b3e5
- affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < da16c31517cd2c06bb2c78c73e91ae192c01c426
- affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 – < 816e90057ab1879562a5b7cc688e35bb9027ae97
- affected 2.6.12
- unaffected < 2.6.12
- unaffected 5.10.270 – ≤ 5.10.*
- unaffected 5.15.221 – ≤ 5.15.*
- unaffected 6.1.188 – ≤ 6.1.*
- unaffected 6.6.157 – ≤ 6.6.*
- unaffected 6.12.110 – ≤ 6.12.*
- unaffected 6.18.52 – ≤ 6.18.*
- unaffected 7.2.6 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/86799499585af06a9431c9e7782658667bd62650 (opens in a new tab)
- https://git.kernel.org/stable/c/2017c355a5a1af77736cd1739fe922f69b5652dc (opens in a new tab)
- https://git.kernel.org/stable/c/6581a82bf08ba5d4e2a6d4e3080df43315b296c4 (opens in a new tab)
- https://git.kernel.org/stable/c/9d782c662879c3adaaca30e05c36910ad11b9e54 (opens in a new tab)
- https://git.kernel.org/stable/c/d72dbdfaeb5b9b8d884e0e036c3442754379ef74 (opens in a new tab)
- https://git.kernel.org/stable/c/aeb8196ecb95146e3410f635628e6cd47352b3e5 (opens in a new tab)
- https://git.kernel.org/stable/c/da16c31517cd2c06bb2c78c73e91ae192c01c426 (opens in a new tab)
- https://git.kernel.org/stable/c/816e90057ab1879562a5b7cc688e35bb9027ae97 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-81933 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-90072)Record last updated .