gVisor is a step further: it acts a bit like a user mode kernel, which handles syscalls and carefully passes them to different components that are individually

gVisor is a step further: it acts a bit like a user mode kernel, which handles syscalls and carefully passes them to different components that are individually insulated with seccomp, etc. The idea there is that even a root escape gets you nowhere because root in the sandbox can never be root in the host. You’d first need to exploit the “usermode kernel“ then you are an unprivileged Linux user with a very strict security profile depending on what component you have exploited. Exploiting the actual kernel would theoretically be a lot harder because the syscall surface is no longer directly exposed.