LiveActive security incident?Get immediate response
CVE Record

CVE-2021-47420: drm/amdkfd: fix a potential ttm->sg memory leak

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: fix a potential ttm->sg memory leak Memory is allocated for ttm->sg by kmalloc in kfd_mem_dmamap_userptr, but isn't freed by kfree in kfd_mem_dmaunmap_userptr. Free it!

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2021-47420 is a Linux kernel memory leak in the AMD KFD graphics/compute driver path. Memory allocated during a user pointer DMA mapping path was not freed during unmapping. The public record does not provide CVSS, CWE, exploitability, or confirmed impact beyond the leak.

Executive priority

Treat this as a routine kernel hygiene issue unless your environment relies heavily on AMD GPU compute or multi-user GPU workloads. The available evidence does not support emergency handling, but affected kernels should be updated through normal security maintenance.

Technical view

The issue is in drm/amdkfd: kfd_mem_dmamap_userptr allocates ttm->sg with kmalloc, while kfd_mem_dmaunmap_userptr failed to release it with kfree. Kernel stable commits correct the missing free. The source bundle identifies Linux 5.14-era versions, including before 5.14.12 and 5.15 context, as affected.

Likely exposure

Exposure is most likely on Linux systems running affected kernels with the drm/amdkfd AMD GPU compute driver code present or enabled. The sources do not identify specific distributions, appliances, cloud images, or default configurations.

Exploitation context

There is no KEV listing and no cited source in the bundle claiming active exploitation or public weaponization. The documented weakness is a kernel memory leak, which may matter more on multi-user or long-running GPU compute systems if reachable.

Researcher notes

The public record is sparse: no CVSS, CWE, exploit requirements, or detailed reachability analysis are provided. The safest conclusion is a fixed kernel memory leak in drm/amdkfd, not a confirmed actively exploited vulnerability.

Mitigation direction

  • Upgrade to a vendor kernel containing the referenced stable fixes or equivalent backport.
  • Check Linux distribution advisories for the exact fixed package version.
  • Prioritize systems using AMD GPU compute or KFD functionality.
  • Restart affected systems after kernel updates if required by the vendor.
  • If no update is available, follow vendor guidance for temporary risk reduction.

Validation and detection

  • Inventory Linux kernel versions across AMD GPU-capable systems.
  • Confirm whether the referenced stable commits or equivalent backports are present.
  • Check distribution security advisories for CVE-2021-47420 coverage.
  • Review whether drm/amdkfd is enabled or used on exposed systems.
  • Monitor long-running GPU workloads for unexplained kernel memory growth.
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

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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-47420 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
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
LinuxLinux264fb4d332f5e76743818480e482464437837c52, 264fb4d332f5e76743818480e482464437837c52unaffected
LinuxLinux5.14, 0, 5.14.12, 5.15affected
Weakness

CWE details

No CWE listed

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