CVSS7.8
Severityhigh
Weakness—
ExploitedNot in CISA KEV
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Description
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_