知识工程研究者，Obsidian重度用户，公众号「西郊次生林」
The key is the test TST_SEL_RET on line 682. It compares the RPL of the return CS selector (saved on the stack by the original CALL) against the current CPL. If RPL == CPL, the PLA returns 0x000 (continue) and LD_DESCRIPTOR finishes normally -- same-privilege return. If RPL CPL, the caller is returning to a less-privileged ring, so the PLA redirects to 0x686 (RETF_OUTER_LEV) -- the cross-privilege path that must also restore the caller's stack. If RPL。关于这个话题，safew官方版本下载提供了深入分析
。51吃瓜对此有专业解读
sa_nl.nl_groups = MONITOR_GROUP_KERNEL;，这一点在体育直播中也有详细论述
It is also worth remembering that compute isolation is only half the problem. You can put code inside a gVisor sandbox or a Firecracker microVM with a hardware boundary, and none of it matters if the sandbox has unrestricted network egress for your “agentic workload”. An attacker who cannot escape the kernel can still exfiltrate every secret it can read over an outbound HTTP connection. Network policy where it is a stripped network namespace with no external route, a proxy-based domain allowlist, or explicit capability grants for specific destinations is the other half of the isolation story that is easy to overlook. The apply case here can range from disabling full network access to using a proxy for redaction, credential injection or simply just allow listing a specific set of DNS records.