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CVE Record

CVE-2021-46917: dmaengine: idxd: fix wq cleanup of WQCFG registers

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix wq cleanup of WQCFG registers A pre-release silicon erratum workaround where wq reset does not clear WQCFG registers was leaked into upstream code. Use wq reset command instead of blasting the MMIO region. This also address an issue where we clobber registers in future devices.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue concerns cleanup of idxd work queue configuration registers. The upstream code kept a pre-release hardware workaround that could write across an MMIO region and affect registers on future devices. The business risk is unclear because no CVSS score, CWE, impact statement, or exploitation evidence is provided.

Executive priority

Treat this as a normal kernel maintenance item unless your environment depends on affected idxd hardware paths. There is no cited exploitation evidence, but kernel register-handling defects should not remain untracked on production systems.

Technical view

CVE-2021-46917 is fixed by changing idxd work queue cleanup to use the work queue reset command instead of manually clearing WQCFG MMIO registers. Sources state the previous behavior came from a pre-release silicon erratum workaround and could clobber registers in future devices.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions with the dmaengine idxd driver path relevant. The source lists affected Linux kernel versions including 5.8, 5.10.32, 5.11.16, and 5.12, but does not provide distribution package mappings.

Exploitation context

The source bundle marks this CVE as not in KEV and provides no public exploitation claim. The available description is a kernel correctness and hardware-register handling fix, not evidence of active exploitation or a documented attack path.

Researcher notes

Evidence is sparse: no CVSS, CWE, privilege requirement, crash impact, or exploitability analysis is included. The strongest source detail is the upstream fix rationale: replace manual WQCFG MMIO clearing with a work queue reset to avoid clobbering registers.

Mitigation direction

  • Update affected Linux kernels through trusted vendor or distribution channels.
  • Confirm the update includes one of the referenced stable kernel fixes.
  • Prioritize systems where the idxd dmaengine driver is enabled or relevant.
  • Monitor Linux and distribution advisories for impact or backport clarification.

Validation and detection

  • Inventory Linux kernel versions across servers and appliances.
  • Check vendor kernel changelogs for CVE-2021-46917 or referenced commit IDs.
  • Identify whether the idxd dmaengine driver is present or loaded.
  • Record exceptions where vendor backports fix the issue without version changes.
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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2021-46917 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
3Timeline events
2ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

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.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxda32b28c95a79e399e18c03f8178f41aec9c66e4, da32b28c95a79e399e18c03f8178f41aec9c66e4, da32b28c95a79e399e18c03f8178f41aec9c66e4, 2a2df2bd10de44c3804661ed15157817c12d6291, 5.7.10unaffected
LinuxLinux5.8, 0, 5.10.32, 5.11.16, 5.12affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.