From 511e11af60536dc8d15f920d7c2fdb0c41501ab5 Mon Sep 17 00:00:00 2001
From: Rambo Wang <rambowang@google.com>
Date: Tue, 16 Nov 2021 17:51:34 -0800
Subject: [PATCH] Do not allow null signal thresholds in
 SignalStrengthUpdateRequest

SignalStrengthUpdateRequest is designed to not allow null nor empty
signal thresholds for public apps.

To support system privileged app (Bluetooth) which is only interested
in requiring to report system thresholds while idle. An exemption was
made (aosp/1569861) which was to allow empty thresholds but the null
thresholds was also allowed by mistake. This will cause Bluetooth
crash if no signal thresholds are set.

To fix the issue, we only allow Bluetooth to set EMPTY thresholds
but not null one.

Bug: 205585585
Test: atest SignalStrengthUpdateRequestTest
Change-Id: I245ecb87ab807a6005b32fa320c8820a2c0b1a9e
---
 .../telephony/SignalStrengthUpdateRequest.java    | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/telephony/java/android/telephony/SignalStrengthUpdateRequest.java b/telephony/java/android/telephony/SignalStrengthUpdateRequest.java
index 2ff4ac5e30d3a..9cb80f1814f9d 100644
--- a/telephony/java/android/telephony/SignalStrengthUpdateRequest.java
+++ b/telephony/java/android/telephony/SignalStrengthUpdateRequest.java
@@ -71,12 +71,7 @@ public final class SignalStrengthUpdateRequest implements Parcelable {
             @Nullable List<SignalThresholdInfo> signalThresholdInfos,
             boolean isReportingRequestedWhileIdle,
             boolean isSystemThresholdReportingRequestedWhileIdle) {
-        // System app (like Bluetooth) can specify the request to report system thresholds while
-        // device is idle (with permission protection). In this case, the request doesn't need to
-        // provide a non-empty list of SignalThresholdInfo which is only asked for public apps.
-        if (!isSystemThresholdReportingRequestedWhileIdle) {
-            validate(signalThresholdInfos);
-        }
+        validate(signalThresholdInfos, isSystemThresholdReportingRequestedWhileIdle);
 
         mSignalThresholdInfos = signalThresholdInfos;
         mIsReportingRequestedWhileIdle = isReportingRequestedWhileIdle;
@@ -274,8 +269,12 @@ public final class SignalStrengthUpdateRequest implements Parcelable {
      * Throw IAE if SignalThresholdInfo collection is null or empty,
      * or the SignalMeasurementType for the same RAN in the collection is not unique.
      */
-    private static void validate(Collection<SignalThresholdInfo> infos) {
-        if (infos == null || infos.isEmpty()) {
+    private static void validate(Collection<SignalThresholdInfo> infos,
+            boolean isSystemThresholdReportingRequestedWhileIdle) {
+        // System app (like Bluetooth) can specify the request to report system thresholds while
+        // device is idle (with permission protection). In this case, the request doesn't need to
+        // provide a non-empty list of SignalThresholdInfo which is only asked for public apps.
+        if (infos == null || (infos.isEmpty() && !isSystemThresholdReportingRequestedWhileIdle)) {
             throw new IllegalArgumentException("SignalThresholdInfo collection is null or empty");
         }