The V3 approach obliterates this race condition by hooking addSourceBuffer at the MediaSource.prototype level, I intercept the creation of every SourceBuffer. The moment a buffer is created and returned, I immediately install a hooked appendBuffer directly on that specific instance; before any page code can even see the instance, let alone cache a reference to its methods. The hooked appendBuffer is installed as an own property of the instance, which takes precedence over the prototype chain. There is no window for fermaw to cache the original. The hook is always first.
The code runs as a standard Linux process. Seccomp acts as a strict allowlist filter, reducing the set of permitted system calls. However, any allowed syscall still executes directly against the shared host kernel. Once a syscall is permitted, the kernel code processing that request is the exact same code used by the host and every other container. The failure mode here is that a vulnerability in an allowed syscall lets the code compromise the host kernel, bypassing the namespace boundaries.
，这一点在下载安装 谷歌浏览器 开启极速安全的 上网之旅。中也有详细论述
│ Allowed Host APIs │ ◄── EXPLICIT CAPABILITIES，推荐阅读爱思助手下载最新版本获取更多信息
环境自由定制：云原生执行与灵活扩展