Kernels should not have resource leaks. A web server that leaks memory implies nothing wrong with the clients, a kernel that leaks memory implies nothing wrong with the user space programs.
It just means that there are cases that the kernel developers didn't think of, just like the people who made Apache didn't think of the Slowloris attack. Heck, a few months ago someone exhausted Linux kernel fds in just by shuffling socket pairs around (just 40 lines of C with three syscalls).
These are problems, ranging from remote DOS attacks, local DOS attacks, to accidental DOS attacks.
It just means that there are cases that the kernel developers didn't think of, just like the people who made Apache didn't think of the Slowloris attack. Heck, a few months ago someone exhausted Linux kernel fds in just by shuffling socket pairs around (just 40 lines of C with three syscalls).
These are problems, ranging from remote DOS attacks, local DOS attacks, to accidental DOS attacks.