CVE-2022-50382

In the Linux kernel, the following vulnerability has been resolved:

padata: Always leave BHs disabled when running ->parallel()

A deadlock can happen when an overloaded system runs ->parallel() in the context of the current task:

padata_do_parallel
  ->parallel()
    pcrypt_aead_enc/dec
      padata_do_serial
        spin_lock(&reorder->lock) // BHs still enabled
          <interrupt>
            ...
              __do_softirq
                ...
                  padata_do_serial
                    spin_lock(&reorder->lock)

It's a bug for BHs to be on in doserial as Steffen points out, so ensure they're off in the "current task" case like they are in padataparallelworker to avoid this situation.