Live › vulnerability › CVE-2026-98558
Go to dashboardWhen a CPU goes offline, the Linux kernel can leave socket buffers stranded on that CPU's deferred-free list. If those buffers hold page pool fragments, tearing down a network device or driver can hang indefinitely; the sources do not describe an attacker gaining code execution or data.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems running a Linux kernel with the affected fix range, where CPUs are taken offline (for example by hotplug or power management) and network devices or drivers using page pools are torn down. The sources do not say which kernel versions are affected or whether a fixed release exists. Systems that never offline CPUs or tear down network drivers at runtime are unlikely to hit it.
No product ranges from the sources yet.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
net: flush skb_defer_nodes in dev_cpu_dead()
When a CPU goes offline, dev_cpu_dead() drains its softnet queues (completion_queue, output_queue, poll_list, process_queue, and input_pkt_queue), but leaves net_hotdata.skb_defer_nodes untouched.
If oldcpu goes offline while holding pending skbs in its skb_defer_nodes lists (e.g. below the sysctl_skb_defer_max >> 1 IPI threshold, or if the IPI races with CPU teardown), those skbs remain stranded until oldcpu is brought back online. If any of these skbs hold page_pool fragments, page_pool_destroy() will stall indefinitely waiting for inflight pages to be returned when a netdev or driver is torn down while oldcpu is offline.
Additionally, if smp_call_function_single_async() fails in kick_defer_list_purge() because the target CPU went offline, reset defer_ipi_scheduled to 0 so future IPI kicks are not blocked when the CPU comes back online.
Also, if oldcpu was the last online CPU on its NUMA node, drain that node's slot across all CPUs so no skbs deferred from that node remain stranded on idle remote CPUs (or if the node itself is subsequently offlined).
Finally, in skb_attempt_defer_free(), re-check cpu_online(cpu) and whether the caller migrated CPUs after llist_add(), flushing the node list if so, to close the preemption TOCTOU race against CPU/node teardown.
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