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

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-19 · updated 2026-10-30
Weakness: CWE-125

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.

Affected products

Linux kernel: from 3.13 before 6.1.175; from 6.2 before 6.6.142; from 6.7 before 6.12.92; from 6.13 before 6.18.34; from 6.19 before 7.0.11; 7.1-rc1, 7.1-rc2, 7.1-rc3, 7.1-rc4, 7.1-rc5 — fixed in 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11
Linux: 3.13 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 6.1.175, 6.6.142, 6.12.92, 6.18.34; Linux 7.1. Check the vendor advisory for mitigations.

References

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