net: flush skb_defer_nodes in dev_cpu_dead()
Summary
| CVE | CVE-2026-98558 |
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-18 16:17:07 UTC |
| Updated | 2026-10-18 16:17:07 UTC |
| Description | 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. |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 68822bdf76f10c3dc80609d4e2cdc1e847429086 c68f4157463448a76893223e117170be8374d773 git |
Not specified |
| CNA |
Linux |
Linux |
affected 68822bdf76f10c3dc80609d4e2cdc1e847429086 06e3f54e8b22040ada01a28343badf1990b4dd7d git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.19 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.19 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.9 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3-rc5 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/c68f4157463448a76893223e117170be8374d773 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/06e3f54e8b22040ada01a28343badf1990b4dd7d |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.