From e8e38a400785b38b459b332196e99606f957587d Mon Sep 17 00:00:00 2001
From: Chris Roberts <code@chrisroberts.org>
Date: Mon, 8 May 2017 15:21:39 -0700
Subject: [PATCH] Halt Vagrant if within WSL and attempting to operate out of
 rootfs

---
 lib/vagrant/errors.rb        |  4 ++++
 lib/vagrant/util/platform.rb | 40 +++++++++++++++++++++---------------
 templates/locales/en.yml     |  8 ++++++++
 3 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/lib/vagrant/errors.rb b/lib/vagrant/errors.rb
index b822644ea..d8d4ba44b 100644
--- a/lib/vagrant/errors.rb
+++ b/lib/vagrant/errors.rb
@@ -895,5 +895,9 @@ module Vagrant
     class WSLVagrantVersionMismatch < VagrantError
       error_key(:wsl_vagrant_version_mismatch)
     end
+
+    class WSLVagrantAccessError < VagrantError
+      error_key(:wsl_vagrant_access_error)
+    end
   end
 end
diff --git a/lib/vagrant/util/platform.rb b/lib/vagrant/util/platform.rb
index 4b744c3e7..3e8d41057 100644
--- a/lib/vagrant/util/platform.rb
+++ b/lib/vagrant/util/platform.rb
@@ -290,22 +290,29 @@ module Vagrant
         # simple setup to allow sharing of the user's VAGRANT_HOME directory
         # within the subsystem
         #
+        # @param [Environment] env
         # @param [Logger] logger Optional logger to display information
-        def wsl_init(logger=nil)
-          if wsl? && ENV["VAGRANT_WSL_ACCESS_WINDOWS_USER"]
-            wsl_validate_matching_vagrant_versions!
-            shared_user = ENV["VAGRANT_WSL_ACCESS_WINDOWS_USER"]
-            if logger
-              logger.warn("Windows Subsystem for Linux detected. Allowing access to user: #{shared_user}")
-              logger.warn("Vagrant will be allowed to control Vagrant managed machines within the user's home path.")
-            end
-            if ENV["VAGRANT_HOME"] || ENV["VAGRANT_WSL_DISABLE_VAGRANT_HOME"]
-              logger.warn("VAGRANT_HOME environment variable already set. Not overriding!") if logger
-            else
-              home_path = wsl_windows_accessible_path
-              ENV["VAGRANT_HOME"] = File.join(home_path, ".vagrant.d")
+        def wsl_init(env, logger=nil)
+          if wsl?
+            if ENV["VAGRANT_WSL_ACCESS_WINDOWS_USER"]
+              wsl_validate_matching_vagrant_versions!
+              shared_user = ENV["VAGRANT_WSL_ACCESS_WINDOWS_USER"]
               if logger
-                logger.info("Overriding VAGRANT_HOME environment variable to configured windows user. (#{ENV["VAGRANT_HOME"]})")
+                logger.warn("Windows Subsystem for Linux detected. Allowing access to user: #{shared_user}")
+                logger.warn("Vagrant will be allowed to control Vagrant managed machines within the user's home path.")
+              end
+              if ENV["VAGRANT_HOME"] || ENV["VAGRANT_WSL_DISABLE_VAGRANT_HOME"]
+                logger.warn("VAGRANT_HOME environment variable already set. Not overriding!") if logger
+              else
+                home_path = wsl_windows_accessible_path
+                ENV["VAGRANT_HOME"] = File.join(home_path, ".vagrant.d")
+                if logger
+                  logger.info("Overriding VAGRANT_HOME environment variable to configured windows user. (#{ENV["VAGRANT_HOME"]})")
+                end
+              end
+            else
+              if env.local_data_path.to_s.start_with?("/mnt/")
+                raise Vagrant::Errors::WSLVagrantAccessError
               end
             end
           end
@@ -319,13 +326,14 @@ module Vagrant
           if result.exit_code == 0
             windows_version = result.stdout.match(/Installed Version: (?<version>.+$)/)
             if windows_version
-              valid = windows_version[:version] == Vagrant::VERSION
+              windows_version = windows_version[:version].strip
+              valid = windows_version == Vagrant::VERSION
             end
           end
           if !valid
             raise Vagrant::Errors::WSLVagrantVersionMismatch,
               wsl_version: Vagrant::VERSION,
-              windows_version: windows_version ? windows_version[:version] : "unknown"
+              windows_version: windows_version || "unknown"
           end
         end
 
diff --git a/templates/locales/en.yml b/templates/locales/en.yml
index 8c08135f9..be8e38c75 100644
--- a/templates/locales/en.yml
+++ b/templates/locales/en.yml
@@ -1530,6 +1530,14 @@ en:
 
           Windows Vagrant version: %{windows_version}
           Windows Subsystem for Linux Vagrant version: %{wsl_version}
+      wsl_vagrant_access_error: |-
+        Vagrant will not operate outside the Windows Subsystem for Linux unless explicitly
+        instructed. Due to the inability to enforce expected Linux file ownership and
+        permissions on the Windows system, Vagrant will not make modifications to prevent
+        unexpected errors. To learn more about this, and the options that are available,
+        please refer to the Vagrant documentation:
+
+          https://www.vagrantup.com/docs/other/wsl
 
 #-------------------------------------------------------------------------------
 # Translations for config validation errors