From 5b29237ed1e426ad6059ed590646c41e75356185 Mon Sep 17 00:00:00 2001
From: Eric Weber <eric.weber@suse.com>
Date: Wed, 14 Aug 2024 10:17:16 -0500
Subject: [PATCH] fix(networking): use mounted /host/proc instead of HostPID

Longhorn 9223

Signed-off-by: Eric Weber <eric.weber@suse.com>
---
 csi/deployment.go | 21 +++++++++++----------
 package/nsmounter | 10 ++++++++--
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/csi/deployment.go b/csi/deployment.go
index 92880e599e..4cf5c3bcfb 100644
--- a/csi/deployment.go
+++ b/csi/deployment.go
@@ -307,7 +307,6 @@ func NewPluginDeployment(namespace, serviceAccount, nodeDriverRegistrarImage, li
 					Tolerations:        tolerations,
 					NodeSelector:       nodeSelector,
 					PriorityClassName:  priorityClass,
-					HostPID:            true,
 					Containers: []corev1.Container{
 						{
 							Name:  "node-driver-registrar",
@@ -447,13 +446,15 @@ func NewPluginDeployment(namespace, serviceAccount, nodeDriverRegistrarImage, li
 									MountPath: "/dev",
 								},
 								{
-									Name:      "host-sys",
-									MountPath: "/sys",
+									// The plugin must be able to switch to the host's namespaces in order to execute
+									// cryptsetup commands for encrypted devices to mount RWX volumes when not using a
+									// storage network.
+									Name:      "host-proc",
+									MountPath: "/host/proc",
 								},
 								{
-									Name:             "host",
-									MountPath:        "/host",
-									MountPropagation: &MountPropagationBidirectional,
+									Name:      "host-sys",
+									MountPath: "/sys",
 								},
 								{
 									Name:      "lib-modules",
@@ -509,18 +510,18 @@ func NewPluginDeployment(namespace, serviceAccount, nodeDriverRegistrarImage, li
 							},
 						},
 						{
-							Name: "host-sys",
+							Name: "host-proc",
 							VolumeSource: corev1.VolumeSource{
 								HostPath: &corev1.HostPathVolumeSource{
-									Path: "/sys",
+									Path: "/proc",
 								},
 							},
 						},
 						{
-							Name: "host",
+							Name: "host-sys",
 							VolumeSource: corev1.VolumeSource{
 								HostPath: &corev1.HostPathVolumeSource{
-									Path: "/",
+									Path: "/sys",
 								},
 							},
 						},
diff --git a/package/nsmounter b/package/nsmounter
index 05ba2647e3..1d7015599c 100755
--- a/package/nsmounter
+++ b/package/nsmounter
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-PROC_DIR="/proc"
+PROC_DIR="/host/proc"
 
 os_distro_talos="talos"
 os_distro=""
@@ -43,4 +43,10 @@ get_os_distro
 
 [[ $os_distro = $os_distro_talos ]] && get_pid "kubelet"
 
-nsenter -t $target_pid -m -n -u -- "$@"
\ No newline at end of file
+# Use namespace files instead of -t to avoid the need for HostPID.
+ns_dir="$PROC_DIR/$target_pid/ns"
+ns_mnt="$ns_dir/mnt"
+ns_net="$ns_dir/net"
+ns_uts="$ns_dir/uts"
+
+nsenter --mount="$ns_mnt" --net="$ns_net" --uts="$ns_uts" -- "$@"