Validate package name passed to setApplicationRestrictions. (Reland)
This adds validation that the package name passed to
setApplicationRestrictions is in the correct format. This will avoid
an issue where a path could be entered resulting in a file being
written to an unexpected place.
Bug: 239701237
Merged-In: I1ab2b7228470f10ec26fe3a608ae540cfc9e9a96
Change-Id: I56c2fc14f906cdad80181ab577e2ebc276c151c1
diff --git a/services/core/java/com/android/server/pm/UserManagerService.java b/services/core/java/com/android/server/pm/UserManagerService.java
index 09c6b50..92abc486 100644
--- a/services/core/java/com/android/server/pm/UserManagerService.java
+++ b/services/core/java/com/android/server/pm/UserManagerService.java
@@ -88,6 +88,7 @@
import android.util.ArrayMap;
import android.util.ArraySet;
import android.util.AtomicFile;
+import android.util.EventLog;
import android.util.IndentingPrintWriter;
import android.util.IntArray;
import android.util.Slog;
@@ -4499,6 +4500,13 @@
public void setApplicationRestrictions(String packageName, Bundle restrictions,
@UserIdInt int userId) {
checkSystemOrRoot("set application restrictions");
+ String validationResult = validateName(packageName);
+ if (validationResult != null) {
+ if (packageName.contains("../")) {
+ EventLog.writeEvent(0x534e4554, "239701237", -1, "");
+ }
+ throw new IllegalArgumentException("Invalid package name: " + validationResult);
+ }
if (restrictions != null) {
restrictions.setDefusable(true);
}
@@ -4525,6 +4533,39 @@
mContext.sendBroadcastAsUser(changeIntent, UserHandle.of(userId));
}
+ /**
+ * Check if the given name is valid.
+ *
+ * Note: the logic is taken from FrameworkParsingPackageUtils in master, edited to remove
+ * unnecessary parts. Copied here for a security fix.
+ *
+ * @param name The name to check.
+ * @return null if it's valid, error message if not
+ */
+ @VisibleForTesting
+ static String validateName(String name) {
+ final int n = name.length();
+ boolean front = true;
+ for (int i = 0; i < n; i++) {
+ final char c = name.charAt(i);
+ if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
+ front = false;
+ continue;
+ }
+ if (!front) {
+ if ((c >= '0' && c <= '9') || c == '_') {
+ continue;
+ }
+ if (c == '.') {
+ front = true;
+ continue;
+ }
+ }
+ return "bad character '" + c + "'";
+ }
+ return null;
+ }
+
private int getUidForPackage(String packageName) {
final long ident = Binder.clearCallingIdentity();
try {
