Hunting Down a Go Runtime Bug on 32-Bit Embedded Systems

A Go runtime bug causing crashes on 32-bit embedded Linux systems (ARM and i386) was traced to the netpoll mechanism unexpectedly receiving EPOLLOUT events alongside EPOLLIN, violating an internal assumption in the code. The issue, which had been open since March 2025 with no accepted fix, was investigated by security engineers who identified it as a 32-bit specific problem unrelated to epoll kernel behavior itself. The team used code review and analysis tools to determine the root cause and work toward a solution for the Go maintainers.