Fix NPE in BssidBlocklistMonitor

Due to unexpected orderings of events happening in ClientModeImpl,
sometimes invalid inputs are being passed to BssidBlocklistMonitor to
cause a NPE.

This patch fixes the crash but does not address the root cause.

Bug: 159183809
Test: atest com.android.server.wifi
Change-Id: I6991b29949f9799662b8d29a4e0621fed9ff8cf2

2 files changed, 29 insertions, 0 deletions

diff --git a/service/java/com/android/server/wifi/BssidBlocklistMonitor.java b/service/java/com/android/server/wifi/BssidBlocklistMonitor.java
index 96770443d..dffd77443 100644
--- a/service/java/com/android/server/wifi/BssidBlocklistMonitor.java
+++ b/service/java/com/android/server/wifi/BssidBlocklistMonitor.java
@@ -220,6 +220,12 @@ public class BssidBlocklistMonitor {
      */
     public void blockBssidForDurationMs(@NonNull String bssid, @NonNull String ssid,
             long durationMs) {
+        if (bssid == null || ssid == null || WifiManager.UNKNOWN_SSID.equals(ssid)
+                || bssid.equals(ClientModeImpl.SUPPLICANT_BSSID_ANY) || durationMs <= 0) {
+            Log.e(TAG, "Invalid input: BSSID=" + bssid + ", SSID=" + ssid
+                    + ", durationMs=" + durationMs);
+            return;
+        }
         BssidStatus status = getOrCreateBssidStatus(bssid, ssid);
         if (status.isInBlocklist
                 && status.blocklistEndTimeMs - mClock.getWallClockMillis() > durationMs) {
@@ -407,6 +413,9 @@ public class BssidBlocklistMonitor {
         int prevSize = mBssidStatusMap.size();
         mBssidStatusMap.entrySet().removeIf(e -> {
             BssidStatus status = e.getValue();
+            if (status.ssid == null) {
+                return false;
+            }
             if (status.ssid.equals(ssid)) {
                 mBssidStatusHistoryLogger.add(status, "clearBssidBlocklistForSsid");
                 return true;
diff --git a/tests/wifitests/src/com/android/server/wifi/BssidBlocklistMonitorTest.java b/tests/wifitests/src/com/android/server/wifi/BssidBlocklistMonitorTest.java
index 4369a831b..8cb2e376a 100644
--- a/tests/wifitests/src/com/android/server/wifi/BssidBlocklistMonitorTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/BssidBlocklistMonitorTest.java
@@ -662,4 +662,24 @@ public class BssidBlocklistMonitorTest {
         assertEquals(0, mBssidBlocklistMonitor.updateAndGetBssidBlocklist().size());
         assertEquals(2, mBssidBlocklistMonitor.getBssidStatusHistoryLoggerSize());
     }
+
+    /**
+     * Verify that invalid inputs are handled and result in no-op.
+     */
+    @Test
+    public void testBlockBssidForDurationMsInvalidInputs() {
+        // test invalid BSSID
+        when(mClock.getWallClockMillis()).thenReturn(0L);
+        long testDuration = 5500L;
+        mBssidBlocklistMonitor.blockBssidForDurationMs(null, TEST_SSID_1, testDuration);
+        assertEquals(0, mBssidBlocklistMonitor.updateAndGetBssidBlocklist().size());
+
+        // test invalid SSID
+        mBssidBlocklistMonitor.blockBssidForDurationMs(TEST_BSSID_1, null, testDuration);
+        assertEquals(0, mBssidBlocklistMonitor.updateAndGetBssidBlocklist().size());
+
+        // test invalid duration
+        mBssidBlocklistMonitor.blockBssidForDurationMs(TEST_BSSID_1, TEST_SSID_1, -1);
+        assertEquals(0, mBssidBlocklistMonitor.updateAndGetBssidBlocklist().size());
+    }
 }