Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-08-15T00:00:00 kernel: net/sched: sch_multiq: Replace direct dequeue call with peek and qdisc_dequeue_peeked 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-476

In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_multiq: Replace direct dequeue call with peek and qdisc_dequeue_peeked multiq_dequeue() takes a packet from a band's child with a direct ->dequeue() call after multiq_peek() peeked it. When the child is non-work-conserving the peek stashes the skb in the child's gso_skb, so the direct dequeue returns a different skb and orphans the stash, desyncing the child's qlen/backlog. With a qfq child reached through a peeking parent (e.g. tbf) this re-enters the child on an emptied list and dereferences NULL, panicking the kernel from softirq on ordinary egress. Take the packet through qdisc_dequeue_peeked(), as sch_prio already does and as sch_red and sch_sfb were just fixed to do. The helper is a no-op when the child has no stash, so a work-conserving child is unaffected.

A flaw was found in the Linux kernel's `sch_multiq` component, which handles network packet scheduling. This vulnerability occurs when a non-work-conserving child queue is improperly handled after a packet has been temporarily stored. This can lead to a desynchronization of network packet queues and a null pointer dereference. An attacker could exploit this by sending specially crafted network traffic, causing the kernel to panic and resulting in a Denial of Service (DoS).

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Out of support scope kernel Red Hat Enterprise Linux 7 Fix deferred kernel Red Hat Enterprise Linux 7 Fix deferred kernel-rt Red Hat Enterprise Linux 8 Fix deferred kernel Red Hat Enterprise Linux 8 Fix deferred kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-72036 https://nvd.nist.gov/vuln/detail/CVE-2026-72036 https://lore.kernel.org/linux-cve-announce/2026081512-CVE-2026-72036-1317@gregkh/T