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CVE Record

CVE-2021-47105: ice: xsk: return xsk buffers back to pool when cleaning the ring

In the Linux kernel, the following vulnerability has been resolved: ice: xsk: return xsk buffers back to pool when cleaning the ring Currently we only NULL the xdp_buff pointer in the internal SW ring but we never give it back to the xsk buffer pool. This means that buffers can be leaked out of the buff pool and never be used again. Add missing xsk_buff_free() call to the routine that is supposed to clean the entries that are left in the ring so that these buffers in the umem can be used by other sockets. Also, only go through the space that is actually left to be cleaned instead of a whole ring.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-47105 is a Linux kernel availability issue in the ice XSK buffer cleanup path. Some packet buffers are removed from the driver ring but not returned to the XSK buffer pool, so they can become unavailable for reuse. The source bundle does not provide CVSS, CWE, or evidence of active exploitation.

Executive priority

Treat as moderate operational priority when affected Linux networking workloads are present. For general Linux estates without ice/XSK usage evidence, urgency is lower but still requires normal kernel maintenance tracking.

Technical view

The ice driver cleanup routine NULLs an internal xdp_buff pointer without calling xsk_buff_free(), leaking buffers from the XSK UMEM pool. The fix returns leftover buffers to the pool and limits cleanup to entries actually remaining in the ring.

Likely exposure

Exposure is most likely on Linux systems running affected kernel builds that use the ice driver with XSK/AF_XDP buffer pools. The provided affected-version data is incomplete and should be verified against distribution kernel advisories.

Exploitation context

The bundle marks KEV as false and provides no public exploitation evidence. The practical risk appears availability-focused: repeated buffer loss could reduce usable packet buffers and disrupt workloads relying on XSK networking.

Researcher notes

Evidence is limited to the CVE description and Linux stable references. No CVSS vector, CWE, exploit status, or distribution-specific package fix is supplied, so exposure validation should focus on kernel version, driver usage, and presence of the cleanup fix.

Mitigation direction

  • Check vendor or distribution advisories for fixed kernel packages.
  • Prioritize updates on hosts using the ice driver with XSK workloads.
  • Track whether referenced stable commits are included in deployed kernels.
  • If updates are delayed, monitor affected hosts for packet processing degradation.

Validation and detection

  • Inventory Linux kernel versions on systems using the ice driver.
  • Confirm whether AF_XDP or XSK buffer pools are used in production.
  • Compare deployed kernel source or changelog with the referenced stable commits.
  • Review operational telemetry for recurring buffer exhaustion or network degradation.
Prepared
Confidence
medium
Sources
4

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-2021-47105 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
3Source 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
LinuxLinux2d4238f5569722197612656163d824098208519c, 2d4238f5569722197612656163d824098208519cunaffected
LinuxLinux5.5, 0, 5.15.12, 5.16affected
Weakness

CWE details

No CWE listed

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