diff --git a/backend/hooks/base.go b/backend/hooks/base.go
index b6cefee..0a2c9e5 100644
--- a/backend/hooks/base.go
+++ b/backend/hooks/base.go
@@ -381,8 +381,10 @@ func Init(serverVersion string) {
 		pluginNo++
 		go waitPlugin(process, logicalID, socketPath, launchSpec)
 		if limitErr := applyPluginResourceLimits(process); limitErr != nil {
-			log.Warnf("[%s] Plugin resource limits could not be applied", logicalID)
-			_ = process.Kill()
+			log.WithError(limitErr).Warnf("[%s] 插件资源限制应用失败，插件未启用", logicalID)
+			if killErr := process.Kill(); killErr != nil && !errors.Is(killErr, os.ErrProcessDone) {
+				log.WithError(killErr).Errorf("[%s] 插件终止失败，请检查服务权限", logicalID)
+			}
 			continue
 		}
 
diff --git a/deploy/systemd/smail.service b/deploy/systemd/smail.service
index 6f951a0..9366d79 100644
--- a/deploy/systemd/smail.service
+++ b/deploy/systemd/smail.service
@@ -35,7 +35,8 @@ RuntimeDirectoryMode=0750
 NoNewPrivileges=true
 AmbientCapabilities=CAP_NET_BIND_SERVICE CAP_DAC_OVERRIDE CAP_DAC_READ_SEARCH CAP_FOWNER
 # 主进程需要读取 smail 用户权限保护的配置和数据目录，同时保留插件隔离能力。
-CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_SYS_CHROOT CAP_SETUID CAP_SETGID CAP_CHOWN CAP_SYS_ADMIN CAP_DAC_OVERRIDE CAP_DAC_READ_SEARCH CAP_FOWNER
+# 跨用户限制资源和终止降权插件分别需要资源管理与信号能力；插件本身不继承有效能力。
+CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_SYS_CHROOT CAP_SETUID CAP_SETGID CAP_CHOWN CAP_SYS_ADMIN CAP_DAC_OVERRIDE CAP_DAC_READ_SEARCH CAP_FOWNER CAP_SYS_RESOURCE CAP_KILL
 PrivateTmp=true
 ProtectHome=true
 ProtectSystem=full