CVE-2026-64312: crypto: pcrypt - restore callback for non-parallel fallback

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-25 · updated 2026-10-24
Weakness: CWE-662

Description

In the Linux kernel, the following vulnerability has been resolved: crypto: pcrypt - restore callback for non-parallel fallback pcrypt installs pcrypt_aead_done() on the child AEAD request before trying to submit it through padata. If padata_do_parallel() returns -EBUSY, pcrypt falls back to calling the child AEAD directly. That fallback must not keep the padata completion callback. Otherwise an asynchronous completion runs pcrypt_aead_done() even though the request was never enrolled in padata. Restore the original request callback and callback data before calling the child AEAD directly. This keeps the fallback path aligned with a direct AEAD request while leaving the parallel path unchanged.

Affected products

Linux kernel: from 4.19.325 before 4.20; from 5.4.287 before 5.5; from 5.10.231 before 5.10.261; from 5.15.174 before 5.15.212; from 6.1.120 before 6.1.178; from 6.6.64 before 6.6.145 — fixed in 4.20, 5.10.261, 5.15.212, 5.5, 6.1.178, 6.12

How to fix

Upgrade to a fixed version: Linux kernel 4.20, 5.10.261, 5.15.212, 5.5. Check the vendor advisory for mitigations.

References

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