pseries/papr-hvpipe: Fix race with interrupt handler

CVE-2026-46298

What is CVE-2026-46298?

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

pseries/papr-hvpipe: Fix race with interrupt handler

While executing ->ioctl handler or ->release handler, if an interrupt fires on the same cpu, then we can enter into a deadlock.

This patch fixes both these handlers to take spin_lock_irq{save|restore} versions of the lock to prevent this deadlock.

References