CVE-2026-98558 (GCVE-0-2026-98558)
Vulnerability from cvelistv5
Published
2026-10-18 15:18
Modified
2026-10-19 09:21
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/core/dev.c",
"net/core/dev.h",
"net/core/skbuff.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "c68f4157463448a76893223e117170be8374d773",
"status": "affected",
"version": "68822bdf76f10c3dc80609d4e2cdc1e847429086",
"versionType": "git"
},
{
"lessThan": "06e3f54e8b22040ada01a28343badf1990b4dd7d",
"status": "affected",
"version": "68822bdf76f10c3dc80609d4e2cdc1e847429086",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/core/dev.c",
"net/core/dev.h",
"net/core/skbuff.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.19"
},
{
"lessThan": "5.19",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.9",
"versionStartIncluding": "5.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "5.19",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: flush skb_defer_nodes in dev_cpu_dead()\n\nWhen a CPU goes offline, dev_cpu_dead() drains its softnet queues\n(completion_queue, output_queue, poll_list, process_queue, and\ninput_pkt_queue), but leaves net_hotdata.skb_defer_nodes untouched.\n\nIf oldcpu goes offline while holding pending skbs in its\nskb_defer_nodes lists (e.g. below the sysctl_skb_defer_max \u003e\u003e 1 IPI\nthreshold, or if the IPI races with CPU teardown), those skbs remain\nstranded until oldcpu is brought back online. If any of these skbs\nhold page_pool fragments, page_pool_destroy() will stall indefinitely\nwaiting for inflight pages to be returned when a netdev or driver is\ntorn down while oldcpu is offline.\n\nAdditionally, if smp_call_function_single_async() fails in\nkick_defer_list_purge() because the target CPU went offline, reset\ndefer_ipi_scheduled to 0 so future IPI kicks are not blocked when the\nCPU comes back online.\n\nAlso, if oldcpu was the last online CPU on its NUMA node, drain that\nnode\u0027s slot across all CPUs so no skbs deferred from that node remain\nstranded on idle remote CPUs (or if the node itself is subsequently\nofflined).\n\nFinally, in skb_attempt_defer_free(), re-check cpu_online(cpu) and\nwhether the caller migrated CPUs after llist_add(), flushing the node\nlist if so, to close the preemption TOCTOU race against CPU/node\nteardown."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-19T09:21:42.443Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/c68f4157463448a76893223e117170be8374d773"
},
{
"url": "https://git.kernel.org/stable/c/06e3f54e8b22040ada01a28343badf1990b4dd7d"
}
],
"title": "net: flush skb_defer_nodes in dev_cpu_dead()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-98558",
"datePublished": "2026-10-18T15:18:25.282Z",
"dateReserved": "2026-09-25T10:25:14.357Z",
"dateUpdated": "2026-10-19T09:21:42.443Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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