Bug 1717599 - Ensure XDG_CONFIG_DIRS / XDG_CONFIG_HOME are non empty r=gcp

Differential Revision: https://phabricator.services.mozilla.com/D118483

security/sandbox/linux/broker/SandboxBrokerPolicyFactory.cpp

@@ -357,14 +357,17 @@ void SandboxBrokerPolicyFactory::InitContentPolicy() {
   // For that we use AddPath(, SandboxBroker::Policy::AddCondition::AddAlways).
   //
   // Allow access to XDG_CONFIG_HOME and XDG_CONFIG_DIRS
-  if (const auto* xdgConfigPath = PR_GetEnv("XDG_CONFIG_HOME")) {
-    policy->AddPath(rdonly, xdgConfigPath,
+  nsAutoCString xdgConfigHome(PR_GetEnv("XDG_CONFIG_HOME"));
+  if (!xdgConfigHome.IsEmpty()) {  // AddPath will fail on empty strings
+    policy->AddPath(rdonly, xdgConfigHome.get(),
                     SandboxBroker::Policy::AddCondition::AddAlways);
   }
   nsAutoCString xdgConfigDirs(PR_GetEnv("XDG_CONFIG_DIRS"));
   for (const auto& path : xdgConfigDirs.Split(':')) {
-    policy->AddPath(rdonly, PromiseFlatCString(path).get(),
-                    SandboxBroker::Policy::AddCondition::AddAlways);
+    if (!path.IsEmpty()) {  // AddPath will fail on empty strings
+      policy->AddPath(rdonly, PromiseFlatCString(path).get(),
+                      SandboxBroker::Policy::AddCondition::AddAlways);
+    }
   }
 
   // Allow fonts subdir in XDG_DATA_HOME

security/sandbox/moz.build

@@ -4,7 +4,11 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-BROWSER_CHROME_MANIFESTS += ["test/browser.ini"]
+BROWSER_CHROME_MANIFESTS += [
+    "test/browser.ini",
+    "test/browser_bug1717599_XDG-CONFIG-DIRS.ini",
+    "test/browser_bug1717599_XDG-CONFIG-HOME.ini",
+]
 
 with Files("**"):
     BUG_COMPONENT = ("Core", "Security: Process Sandboxing")

security/sandbox/test/browser_bug1717599_XDG-CONFIG-DIRS.ini

@@ -0,0 +1,8 @@
+# Any copyright is dedicated to the Public Domain.
+# http://creativecommons.org/publicdomain/zero/1.0/
+[DEFAULT]
+tags = contentsandbox
+environment=XDG_CONFIG_DIRS=:/opt
+
+[browser_content_sandbox_bug1717599_XDG-CONFIG-DIRS.js]
+run-if = (os == 'linux')

security/sandbox/test/browser_bug1717599_XDG-CONFIG-HOME.ini

@@ -0,0 +1,8 @@
+# Any copyright is dedicated to the Public Domain.
+# http://creativecommons.org/publicdomain/zero/1.0/
+[DEFAULT]
+tags = contentsandbox
+environment=XDG_CONFIG_HOME=
+
+[browser_content_sandbox_bug1717599_XDG-CONFIG-HOME.js]
+run-if = (os == 'linux')

security/sandbox/test/browser_content_sandbox_bug1717599_XDG-CONFIG-DIRS.js

@@ -0,0 +1,11 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+/* import-globals-from browser_content_sandbox_utils.js */
+"use strict";
+
+//
+// Just test that browser does not die on empty env var
+//
+add_task(async function() {
+  ok(true, "Process can run");
+});

security/sandbox/test/browser_content_sandbox_bug1717599_XDG-CONFIG-HOME.js

@@ -0,0 +1,11 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+/* import-globals-from browser_content_sandbox_utils.js */
+"use strict";
+
+//
+// Just test that browser does not die on empty env var
+//
+add_task(async function() {
+  ok(true, "Process can run");
+});