CVE-2026-64312: Undefined Security Weakness

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.