diff --git a/service/java/com/android/server/wifi/WifiConfigurationUtil.java b/service/java/com/android/server/wifi/WifiConfigurationUtil.java
index 6e8eb61..11eb0c4 100644
--- a/service/java/com/android/server/wifi/WifiConfigurationUtil.java
+++ b/service/java/com/android/server/wifi/WifiConfigurationUtil.java
@@ -445,7 +445,8 @@
         return true;
     }
 
-    private static boolean validatePassword(String password, boolean isAdd, boolean isSae) {
+    private static boolean validatePassword(String password, boolean isAdd, boolean isSae,
+            boolean isWapi) {
         if (isAdd) {
             if (password == null) {
                 Log.e(TAG, "validatePassword: null string");
@@ -487,7 +488,14 @@
             }
         } else {
             // HEX PSK string
-            if (password.length() != PSK_SAE_HEX_LEN) {
+            if (isWapi) {
+                // Protect system against malicious actors injecting arbitrarily large passwords.
+                if (password.length() > 100) {
+                    Log.e(TAG, "validatePassword failed: WAPI hex string too long: "
+                            + password.length());
+                    return false;
+                }
+            } else if (password.length() != PSK_SAE_HEX_LEN) {
                 Log.e(TAG, "validatePassword failed: hex string size mismatch: "
                         + password.length());
                 return false;
@@ -689,15 +697,15 @@
             return false;
         }
         if (config.isSecurityType(WifiConfiguration.SECURITY_TYPE_PSK)
-                && !validatePassword(config.preSharedKey, isAdd, false)) {
+                && !validatePassword(config.preSharedKey, isAdd, false, false)) {
             return false;
         }
         if (config.isSecurityType(WifiConfiguration.SECURITY_TYPE_SAE)
-                && !validatePassword(config.preSharedKey, isAdd, true)) {
+                && !validatePassword(config.preSharedKey, isAdd, true, false)) {
             return false;
         }
         if (config.isSecurityType(WifiConfiguration.SECURITY_TYPE_WAPI_PSK)
-                && !validatePassword(config.preSharedKey, isAdd, false)) {
+                && !validatePassword(config.preSharedKey, isAdd, false, true)) {
             return false;
         }
         if (!validateEnterpriseConfig(config, isAdd)) {
@@ -846,11 +854,11 @@
             return false;
         }
         if (config.isSecurityType(WifiConfiguration.SECURITY_TYPE_PSK)
-                && !validatePassword(config.preSharedKey, true, false)) {
+                && !validatePassword(config.preSharedKey, true, false, false)) {
             return false;
         }
         if (config.isSecurityType(WifiConfiguration.SECURITY_TYPE_SAE)
-                && !validatePassword(config.preSharedKey, true, true)) {
+                && !validatePassword(config.preSharedKey, true, true, false)) {
             return false;
         }
         // TBD: Validate some enterprise params as well in the future here.
diff --git a/service/tests/wifitests/src/com/android/server/wifi/WifiConfigurationUtilTest.java b/service/tests/wifitests/src/com/android/server/wifi/WifiConfigurationUtilTest.java
index b497bb5..af9b08b 100644
--- a/service/tests/wifitests/src/com/android/server/wifi/WifiConfigurationUtilTest.java
+++ b/service/tests/wifitests/src/com/android/server/wifi/WifiConfigurationUtilTest.java
@@ -433,7 +433,8 @@
         WifiConfiguration config = WifiConfigurationTestUtil.createWapiPskNetwork();
         assertTrue(WifiConfigurationUtil.validate(config, WifiConfigurationUtil.VALIDATE_FOR_ADD));
 
-        config.preSharedKey = "abcd123456788990013453445345465465476546";
+        config.preSharedKey = "01234567890123456789012345678901234567890123456789012345678901234567"
+                + "890123456789012345678901234567890";
         assertFalse(WifiConfigurationUtil.validate(config, WifiConfigurationUtil.VALIDATE_FOR_ADD));
         config.preSharedKey = "";
         assertFalse(WifiConfigurationUtil.validate(config, WifiConfigurationUtil.VALIDATE_FOR_ADD));