CVE-2026-68152 (GCVE-0-2026-68152)
Vulnerability from cvelistv5
Published
2026-08-10 11:59
Modified
2026-08-17 04:59
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
amt: fix use-after-free in AMT delayed works
When an AMT device is removed, pending delayed works can still access
the freed amt_dev structure, which may result in kernel crashes or
memory corruption.
amt_dev_stop() cancels req_wq and discovery_wq with
cancel_delayed_work_sync(), but these works can be scheduled again
from event_wq after the cancellation. This allows delayed works to
access the freed amt_dev structure after the netdev has been released.
The following is a simple race scenario:
CPU0 CPU1
amt_dev_stop()
cancel_delayed_work_sync()
amt_event_work()
mod_delayed_work(req_wq)
free netdev
req_wq accesses freed amt_dev
Use disable_delayed_work_sync() in amt_dev_stop() to prevent req_wq and
discovery_wq from being queued again and wait for running work items
to complete.
The delayed works are disabled after initialization in
amt_newlink() and enabled only when the device is successfully opened.
This keeps the delayed work lifecycle synchronized with the lifetime
of the AMT device.
References
| URL | Tags | |
|---|---|---|
Impacted products
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"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\namt: fix use-after-free in AMT delayed works\n\nWhen an AMT device is removed, pending delayed works can still access\nthe freed amt_dev structure, which may result in kernel crashes or\nmemory corruption.\n\namt_dev_stop() cancels req_wq and discovery_wq with\ncancel_delayed_work_sync(), but these works can be scheduled again\nfrom event_wq after the cancellation. This allows delayed works to\naccess the freed amt_dev structure after the netdev has been released.\n\nThe following is a simple race scenario:\n\nCPU0 CPU1\n\namt_dev_stop()\ncancel_delayed_work_sync()\n amt_event_work()\n mod_delayed_work(req_wq)\nfree netdev\n req_wq accesses freed amt_dev\n\nUse disable_delayed_work_sync() in amt_dev_stop() to prevent req_wq and\ndiscovery_wq from being queued again and wait for running work items\nto complete.\n\nThe delayed works are disabled after initialization in\namt_newlink() and enabled only when the device is successfully opened.\nThis keeps the delayed work lifecycle synchronized with the lifetime\nof the AMT device."
}
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"metrics": [
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"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
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"scenarios": [
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"lang": "en",
"value": "AV:L - Exploitation requires triggering amt_dev_stop() via local rtnetlink (RTM_DELLINK/ip link del) or ndo_stop on an AMT gateway netdev; the UAF race in teardown is not reachable by remote UDP alone without this privileged local device-removal path.\nAC:L - The attacker controls both sides of the race by concurrently deleting/bringing down the AMT interface while flooding AMT UDP packets or letting discovery/request timers fire, reliably re-queuing req_wq/discovery_wq via amt_event_work during the cancel_work_sync window.\nPR:L - Creating, opening, and removing AMT virtual interfaces requires CAP_NET_ADMIN via rtnetlink, which unprivileged users can obtain inside a user network namespace (unshare -Urn), but not without any privileges at all.\nUI:N - No victim user interaction is required; a single attacker with namespace CAP_NET_ADMIN can create an AMT gateway, bring it up, and race interface teardown against self-generated AMT traffic or delayed-work events.\nS:U - Successful exploitation corrupts kernel heap memory and can escalate privileges within the same kernel, but does not inherently cross VM, container, or IOMMU security boundaries into a separate authority domain.\nC:H - Use-after-free of the amt_dev structure embedded in netdev private data allows accessing attacker-influenced freed heap memory, enabling arbitrary kernel memory disclosure through standard UAF exploitation techniques.\nI:H - The UAF on amt_dev delayed-work handlers can corrupt kernel heap metadata and adjacent objects, providing primitives for arbitrary kernel memory writes and potential code execution as acknowledged in the fix commit.\nA:H - Use-after-free in amt_req_work/amt_discovery_work accessing freed amt_dev during netdev teardown can cause kernel oops, panic, or hang, and the fix commit explicitly warns of kernel crashes and memory corruption."
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"dateUpdated": "2026-08-17T04:59:47.614Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
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"url": "https://git.kernel.org/stable/c/a46bfa01e01df0f6f6dc4b0be18db002d6d2dbd2"
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"url": "https://git.kernel.org/stable/c/1a644db2cf59f164cdf3c75995bab5aadc097528"
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"url": "https://git.kernel.org/stable/c/006340cf06881b6ff49767d8b6f3c4f7b892670c"
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{
"url": "https://git.kernel.org/stable/c/ea20c44935d6142daecfa9b39d635033a7553e1b"
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],
"title": "amt: fix use-after-free in AMT delayed works",
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"cveId": "CVE-2026-68152",
"datePublished": "2026-08-10T11:59:18.270Z",
"dateReserved": "2026-07-30T09:28:09.371Z",
"dateUpdated": "2026-08-17T04:59:47.614Z",
"state": "PUBLISHED"
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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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