CVE-2025-39749 rcu: Protect ->defer_qs_iw_pending from data race

In the Linux kernel, the following vulnerability has been resolved: rcu: Protect -deferqsiwpending from data race On kernels built with CONFIGIRQWORK=y, when rcureadunlock is invoked within an interrupts-disabled region of code 1, it will invoke rcureadunlockspecial, which uses an irq-work handle...