softirq

Softirq is a Linux kernel mechanism for deferring interrupt handling to a safe context. A recent thread discusses CVE-2025-37808, a bug in the kernel's crypto subsystem where a null crypto algorithm was protected by a sleeping mutex but could be freed in softirq context via AF_ALG. The fix replaced the mutex with a spinlock to prevent kernel crashes and denial-of-service conditions. This highlights the importance of using appropriate synchronization primitives in softirq context, where sleeping is not allowed. The tag covers Linux kernel development, security vulnerabilities, and interrupt handling best practices.