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CVE Record

CVE-2026-43447: iavf: fix PTP use-after-free during reset

In the Linux kernel, the following vulnerability has been resolved: iavf: fix PTP use-after-free during reset Commit 7c01dbfc8a1c5f ("iavf: periodically cache PHC time") introduced a worker to cache PHC time, but failed to stop it during reset or disable. This creates a race condition where `iavf_reset_task()` or `iavf_disable_vf()` free adapter resources (AQ) while the worker is still running. If the worker triggers `iavf_queue_ptp_cmd()` during teardown, it accesses freed memory/locks, leading to a crash. Fix this by calling `iavf_ptp_release()` before tearing down the adapter. This ensures `ptp_clock_unregister()` synchronously cancels the worker and cleans up the chardev before the backing resources are destroyed.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A timing flaw in the Linux iavf driver can leave background PTP work running while network-adapter resources are being destroyed. The worker may then access freed memory or locks and crash the host. Triggering requires local, low-privileged access according to the supplied CVSS assessment.

Executive priority

Treat this as an expedited infrastructure patch for hosts using iavf with PTP, especially systems requiring high availability. The immediate documented business risk is host instability or outage during adapter teardown. Systems without the affected driver or functionality can follow normal vulnerability triage after exposure is verified.

Technical view

A PHC-time caching worker introduced by commit 7c01dbfc8a1c5f can race with iavf reset or disable operations. Teardown may free adapter AQ resources before the worker calls iavf_queue_ptp_cmd(), causing use-after-free access. The fix invokes iavf_ptp_release() first, synchronously cancelling the worker and removing its character device.

Likely exposure

Exposure is most likely on affected Linux kernels where the iavf driver and PTP functionality are active, particularly when virtual-function reset or disable operations occur. The supplied version data names 6.15, 6.18.19, 6.19.9, and 7.0, but does not provide a clear distribution-package mapping.

Exploitation context

The supplied CVSS score is 7.8 with local access, low complexity, and low privileges required. CISA KEV status is false, and the sources provide no evidence of active exploitation or a public exploit. The description directly establishes a race-triggered crash; broader confidentiality or integrity impact is not demonstrated in the bundle.

Researcher notes

The core issue is teardown ordering: asynchronous PHC caching survives long enough to touch AQ memory or locks after release. ptp_clock_unregister() is relied upon for synchronous worker cancellation. The bundle lists three stable commits, but does not clearly associate each commit with exact release branches or prove impacts beyond crashing.

Mitigation direction

  • Apply a vendor or distribution kernel update containing the referenced stable fix.
  • Confirm the selected package includes iavf_ptp_release() before adapter teardown.
  • Consult distribution guidance where affected and fixed package versions remain unclear.
  • Prioritize hosts using iavf with PTP and frequent virtual-function resets or disable operations.

Validation and detection

  • Inventory Linux kernel versions on systems using the iavf driver.
  • Determine whether PTP functionality is configured for affected iavf interfaces.
  • Map installed distribution packages to one of the referenced stable fixes.
  • Review system logs for driver or kernel crashes around iavf reset and disable events.
  • After updating, confirm the running kernel contains the applicable fix.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2026-43447 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
0ADP providers
4Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-43447Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux7c01dbfc8a1c5f8b8e4a7907ab06db1449d478d0, 7c01dbfc8a1c5f8b8e4a7907ab06db1449d478d0, 7c01dbfc8a1c5f8b8e4a7907ab06db1449d478d0unaffected
LinuxLinux6.15, 0, 6.18.19, 6.19.9, 7.0affected
Weakness

CWE details

No CWE listed

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