Bug 2516682 (CVE-2026-72035) - CVE-2026-72035 kernel: net/sched: sch_taprio: Replace direct dequeue call with peek and qdisc_dequeue_peeked
Summary: CVE-2026-72035 kernel: net/sched: sch_taprio: Replace direct dequeue call wit...
Keywords:
Status: NEW
Alias: CVE-2026-72035
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 06:25 UTC by OSIDB Bzimport
Modified: 2026-08-17 17:15 UTC (History)
2 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-08-15 06:25:36 UTC
In the Linux kernel, the following vulnerability has been resolved:

net/sched: sch_taprio: Replace direct dequeue call with peek and qdisc_dequeue_peeked

When taprio's software path peeks a non-work-conserving child qdisc, the
child stashes the peeked skb in its gso_skb; taprio_dequeue_from_txq()
then takes the packet with a direct child ->dequeue() call, which ignores
that stash, orphans the peeked skb and desyncs the child's qlen/backlog.
With a qfq child 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_red and sch_sfb
now do. The helper returns the child's stashed skb first and is a no-op
when there is none, so a work-conserving child is unaffected and the
gated path now consumes the skb whose length was charged to the budget.


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