AZL-102557
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-102557.json
- JSON Data
- https://api.osv.dev/v1/vulns/AZL-102557
- Upstream
- Published
- 2026-09-17T17:16:56Z
- Modified
- 2026-09-18T14:17:50Z
- Summary
- CVE-2026-90073 affecting package kernel 6.6.150.1-1
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
net/sched: hhf: clamp quantum before hhf_change() to avoid overflow
hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with no overflow check. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes weight * quantum overflow the signed deficit in hhf_dequeue(), spinning forever.
Clamp q->quantum before hhf_change() so both the opt and !opt paths see a sane quantum. Without this, bare "tc qdisc add ... hhf" succeeds with a clamped quantum but "tc qdisc add ... hhf limit 1000" (any option present) fails with -EINVAL because hhf_change() re-validates the unclamped default (sch_hhf.c:559). 256 matches fq_codel's floor and is a sane minimum for a DRR quantum.
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.
- References