CVE Catalog

CVE-2026-74750

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.36%

29th percentile - higher than 29% of all known CVEs

Summary

In the Linux kernel's ovpn module, key slot crypto freeing is performed from an RCU callback, which is unsafe because crypto_free_aead can sleep (e.g., for hardware implementations). The fix defers the freeing to a workqueue where sleeping is allowed.

Risk Assessment

The current implementation may lead to synchronization issues and potential crashes with certain crypto implementations. The fix ensures safe resource release.

Recommendation

Apply a Linux kernel update that includes the fix using queue_rcu_work for key-slot release to avoid sleeping in RCU context.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ovpn: defer key slot crypto freeing to workqueue Key slots are released through a kref and the existing release path frees the AEAD transforms from an RCU callback. That is not safe for all crypto implementations: crypto_free_aead can sleep, for example when an async or hardware implementation has teardown work to complete. Use queue_rcu_work for key-slot release. This keeps the RCU grace period needed by lockless key-slot readers, but runs the actual crypto teardown from workqueue context where sleeping is allowed. Once the rcu_work callback runs, pre-existing RCU readers are gone, and the final kref put already proves that no transform user remains, so the worker can release the AEAD transforms and free the slot directly. The previous patch drains ovpn_wq during module exit, so queued key-slot teardown work cannot outlive module text.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS