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CVE Record

CVE-2021-47190: perf bpf: Avoid memory leak from perf_env__insert_btf()

In the Linux kernel, the following vulnerability has been resolved: perf bpf: Avoid memory leak from perf_env__insert_btf() perf_env__insert_btf() doesn't insert if a duplicate BTF id is encountered and this causes a memory leak. Modify the function to return a success/error value and then free the memory if insertion didn't happen. v2. Adds a return -1 when the insertion error occurs in perf_env__fetch_btf. This doesn't affect anything as the result is never checked.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel perf/BPF memory leak when duplicate BTF metadata is handled. The sources do not show remote code execution, privilege escalation, public exploitation, or CVSS scoring. Treat it as a kernel maintenance and availability hygiene issue until your Linux vendor confirms package exposure and priority.

Executive priority

Set priority after vendor mapping. With no CVSS, KEV listing, or exploitation evidence in the supplied sources, this is not a top emergency signal, but kernel memory leaks can affect reliability and should be included in normal patch cycles.

Technical view

perf_env__insert_btf() could skip inserting a duplicate BTF ID without freeing the allocated memory. The stable fixes make insertion report success or failure and free memory when insertion did not occur. One related change returns an error from perf_env__fetch_btf() on insertion failure, although the source says that result was not checked.

Likely exposure

Exposure is likely limited to Linux systems running affected kernel versions or vendor builds that include the vulnerable perf/BPF code path. The bundle lists Linux 5.1 and fixed-point references around 5.4.162, 5.10.82, 5.15.5, and 5.16, but distro package backports require vendor verification.

Exploitation context

No source in the bundle states active exploitation, public exploit availability, or inclusion in CISA KEV. The described issue is a memory leak from duplicate BTF IDs in perf/BPF handling, so practical risk depends on whether local workloads can exercise that path repeatedly.

Researcher notes

The core evidence is concise: duplicate BTF IDs caused a leak because insertion failure did not trigger cleanup. The available bundle does not establish attack prerequisites, reachable interfaces, security boundaries, or impact magnitude. Avoid assuming remote reachability or privilege escalation without additional vendor or upstream analysis.

Mitigation direction

  • Check your Linux distribution advisory for CVE-2021-47190 package status.
  • Update kernels to vendor-supported builds containing the stable fixes.
  • Prioritize systems using perf, BPF tooling, or intensive observability workflows.
  • Monitor affected hosts for abnormal memory growth during perf/BPF activity.

Validation and detection

  • Inventory kernel versions across Linux servers, workstations, and appliances.
  • Map installed kernels to vendor advisories for CVE-2021-47190.
  • Confirm whether stable fix commits are present in deployed kernel sources.
  • Review observability and performance tooling that uses perf or BPF.
Prepared
Confidence
medium
Sources
6

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-2021-47190 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
5Source 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

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux3792cb2ff43b1b193136a03ce1336462a827d792, 3792cb2ff43b1b193136a03ce1336462a827d792, 3792cb2ff43b1b193136a03ce1336462a827d792, 3792cb2ff43b1b193136a03ce1336462a827d792unaffected
LinuxLinux5.1, 0, 5.4.162, 5.10.82, 5.15.5, 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.