CVE-2026-90074
In the Linux kernel, the following vulnerability has been resolved: net/sched: fq_pie: clamp default quantum to avoid signed overflow fq_pie_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) without clamping. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes psched_mtu() return 0x80000000, which overflows the signed flow->deficit to INT_MIN in fq_pie_qdisc_dequeue(), causing an infinite loop and soft lockup. Emulate fq_pie_policy which is already bounded to [1, 1 << 20]; clamp the default to [256, 1 << 20]. 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.
Affected versions
Linux kernel versions
5.6
and later are affected. Fixed in
5.10.270,
5.15.221,
6.1.188,
6.6.157,
6.12.110,
6.18.52,
7.2.6,
7.3-rc1
and their respective stable series.
References
8 totalFrequently asked questions
-
What is CVE-2026-90074?
CVE-2026-90074 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.6 onward and has been patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-90074 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
Is there a patch available for CVE-2026-90074?
Yes. CVE-2026-90074 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 5.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2026-90074 actively exploited?
No. CVE-2026-90074 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.