[Security] Stop USB device names from being executed as Hyprland Lua (backport of #8129)

Backport of the input-device name fix (PR #8129 by @acrogenesis, merged to
quattro as 9285b19d) onto the v4-0-1 release branch.

Hyprland input-device and monitor names come from USB descriptors and hyprctl
output, so they are attacker-influenceable, yet the toggle and monitor commands
interpolated them straight into hyprctl eval and into generated Lua that
Hyprland re-executes on every reload. XF86TouchpadToggle is bound with
locked = true, so a malicious USB name reached Lua execution from the lock
screen as the logged-in user, and a persisted disable made it run on every
start. Publicly reported by Jorrit Jongma / Chainfire.

The disable is no longer executable Lua anywhere. The device name is stored as
plain-text data in a *-disabled-name sidecar and read back by a packaged module,
default/hypr/disabled-input-device.lua, on every reload; the live hyprctl eval
Lua-quotes the name and rejects control characters outright. The reload loader
excludes the two legacy filenames, so a leftover generated *-disabled.lua on a
not-yet-migrated install can never be sourced as code again, and a migration
recovers the device name from it and deletes it, sanitizing installs that ran
the vulnerable version. All four monitor scripts validate an output name against
a plain-connector-name pattern before writing it as Lua, closing the same latent
pattern in the siblings, and paths.lua treats a set-but-empty XDG_STATE_HOME as
unset to match the bash side.

Clean cherry-pick: all fourteen files are byte-identical to quattro, so merging
v4-0-1 into quattro resolves without a conflict. This branch ships no leftover
*-disabled.lua template of its own -- the tracked "disabled" files are the same
two quattro has -- so the migration is the only path that has to sanitize
anything here.

test/shell passes: 192 files, including the three this adds. The toggle suite's
public-PoC case passes here, as do the monitor scripts' accept/reject cases and
the XDG path cases. test/cli passes.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018DEMYa9UWtroz93DhMTtcV

default/hypr/disabled-input-device.lua

@@ -0,0 +1,21 @@
+-- Disable a Hyprland input device whose name was stored as data, not Lua.
+-- Device names come from USB descriptors and must never be loaded as code.
+
+local paths = require("default.hypr.paths")
+
+return function(kind)
+  -- Hardcoded to ~/.local/state to match omarchy-toggle-input-device and the
+  -- sibling bash toggle tools, which all write there regardless of
+  -- XDG_STATE_HOME.
+  local file = io.open(paths.home .. "/.local/state/omarchy/toggles/hypr/" .. kind .. "-disabled-name", "r")
+  if not file then
+    return
+  end
+
+  local name = file:read("*l")
+  file:close()
+
+  if name and name ~= "" then
+    hl.device({ name = name, enabled = false })
+  end
+end

default/hypr/paths.lua

@@ -4,9 +4,19 @@
 
 local home = os.getenv("HOME")
 
+-- A variable that is set but empty means "unset" (XDG Base Directory spec);
+-- bash's ${VAR:-fallback} in the sibling tools treats it the same way.
+local function env_or(name, fallback)
+  local value = os.getenv(name)
+  if value == nil or value == "" then
+    return fallback
+  end
+  return value
+end
+
 return {
   home = home,
-  config_home = os.getenv("XDG_CONFIG_HOME") or (home .. "/.config"),
-  state_home = os.getenv("XDG_STATE_HOME") or (home .. "/.local/state"),
-  omarchy_path = os.getenv("OMARCHY_PATH") or "/usr/share/omarchy",
+  config_home = env_or("XDG_CONFIG_HOME", home .. "/.config"),
+  state_home = env_or("XDG_STATE_HOME", home .. "/.local/state"),
+  omarchy_path = env_or("OMARCHY_PATH", "/usr/share/omarchy"),
 }

default/hypr/require_all.lua

@@ -4,6 +4,8 @@
 -- Pass a module prefix for normal package.path modules, e.g.
 --   require_all.files(paths.omarchy_path .. "/default/hypr/apps", "default.hypr.apps")
 -- Pass nil as the prefix when the directory itself has been added to package.path.
+-- Pass options.exclude as a set of base names (without ".lua") to skip; a legacy
+-- file that must never be loaded as code stays on disk for a migration to remove.
 
 local M = {}
 
@@ -12,19 +14,23 @@ local function shell_quote(path)
 end
 
 function M.files(dir, module_prefix, options)
+  local exclude = options and options.exclude or {}
   local handle = io.popen("find " .. shell_quote(dir) .. " -maxdepth 1 -type f -name '*.lua' -printf '%f\\n' 2>/dev/null | sort")
   if handle then
     for filename in handle:lines() do
-      local module = filename:gsub("%.lua$", "")
-      if module_prefix then
-        module = module_prefix .. "." .. module
-      end
+      local name = filename:gsub("%.lua$", "")
+      if not exclude[name] then
+        local module = name
+        if module_prefix then
+          module = module_prefix .. "." .. module
+        end
 
-      if options and options.reload then
-        package.loaded[module] = nil
-      end
+        if options and options.reload then
+          package.loaded[module] = nil
+        end
 
-      require(module)
+        require(module)
+      end
     end
     handle:close()
   end

default/hypr/toggles.lua

@@ -4,6 +4,20 @@ local require_all = require("default.hypr.require_all")
 local toggles_dir = paths.state_home .. "/omarchy/toggles/hypr"
 package.path = toggles_dir .. "/?.lua;" .. package.path
 
-require_all.files(toggles_dir, nil, { reload = true })
+-- touchpad-disabled.lua / touchscreen-disabled.lua were generated Lua in older
+-- versions and could carry an injected USB device name. They must never be loaded
+-- as code again: exclude them so a not-yet-migrated install cannot execute a
+-- leftover payload on reload. The migration recovers the name and deletes them.
+require_all.files(toggles_dir, nil, {
+  reload = true,
+  exclude = {
+    ["touchpad-disabled"] = true,
+    ["touchscreen-disabled"] = true,
+  },
+})
+
+local disabled_input_device = require("default.hypr.disabled-input-device")
+disabled_input_device("touchpad")
+disabled_input_device("touchscreen")
 
 require("default.hypr.workspace-layouts")