DivestOS/Patches/LineageOS-15.1/android_frameworks_base/347047-backport.patch
Tad b143ffcd8b
15.1 January ASB work
+ a missing patch from 2019-08

Signed-off-by: Tad <tad@spotco.us>
2023-01-08 16:31:54 -05:00

235 lines
11 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Songchun Fan <schfan@google.com>
Date: Wed, 17 Aug 2022 09:37:18 -0700
Subject: [PATCH] mem limit should be checked before settings are updated
Previously, a setting is updated before the memory usage limit
check, which can be exploited by malicious apps and cause OoM DoS.
This CL changes the logic to checkMemLimit -> update -> updateMemUsage.
BUG: 239415861
Test: atest com.android.providers.settings.SettingsStateTest
(cherry picked from commit 8eeb92950f4a7012d4cf282106a1418fd211f475)
Merged-In: I20551a2dba9aa79efa0c064824f349f551c2c2e4
Change-Id: I20551a2dba9aa79efa0c064824f349f551c2c2e4
(cherry picked from commit d85a42821075ad80b931d904bdc9c1d4c3129456)
Merged-In: I20551a2dba9aa79efa0c064824f349f551c2c2e4
---
.../providers/settings/SettingsState.java | 75 ++++++++++++-------
.../providers/settings/SettingsStateTest.java | 43 ++++++++++-
2 files changed, 90 insertions(+), 28 deletions(-)
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/SettingsState.java b/packages/SettingsProvider/src/com/android/providers/settings/SettingsState.java
index 4151ada9ce80..0e94ea85919b 100644
--- a/packages/SettingsProvider/src/com/android/providers/settings/SettingsState.java
+++ b/packages/SettingsProvider/src/com/android/providers/settings/SettingsState.java
@@ -306,9 +306,11 @@ final class SettingsState {
Setting newSetting = new Setting(name, oldSetting.getValue(), null,
oldSetting.getPackageName(), oldSetting.getTag(), false,
oldSetting.getId());
- mSettings.put(name, newSetting);
- updateMemoryUsagePerPackageLocked(newSetting.getPackageName(), oldValue,
+ int newSize = getNewMemoryUsagePerPackageLocked(newSetting.getPackageName(), oldValue,
newSetting.getValue(), oldDefaultValue, newSetting.getDefaultValue());
+ checkNewMemoryUsagePerPackageLocked(newSetting.getPackageName(), newSize);
+ mSettings.put(name, newSetting);
+ updateMemoryUsagePerPackageLocked(newSetting.getPackageName(), newSize);
scheduleWriteIfNeededLocked();
}
}
@@ -323,6 +325,12 @@ final class SettingsState {
Setting oldState = mSettings.get(name);
String oldValue = (oldState != null) ? oldState.value : null;
String oldDefaultValue = (oldState != null) ? oldState.defaultValue : null;
+ String newDefaultValue = makeDefault ? value : oldDefaultValue;
+
+ int newSize = getNewMemoryUsagePerPackageLocked(packageName, oldValue, value,
+ oldDefaultValue, newDefaultValue);
+ checkNewMemoryUsagePerPackageLocked(packageName, newSize);
+
Setting newState;
if (oldState != null) {
@@ -337,8 +345,7 @@ final class SettingsState {
addHistoricalOperationLocked(HISTORICAL_OPERATION_UPDATE, newState);
- updateMemoryUsagePerPackageLocked(packageName, oldValue, value,
- oldDefaultValue, newState.getDefaultValue());
+ updateMemoryUsagePerPackageLocked(packageName, newSize);
scheduleWriteIfNeededLocked();
@@ -358,10 +365,11 @@ final class SettingsState {
}
Setting oldState = mSettings.remove(name);
-
- updateMemoryUsagePerPackageLocked(oldState.packageName, oldState.value,
+ int newSize = getNewMemoryUsagePerPackageLocked(oldState.packageName, oldState.value,
null, oldState.defaultValue, null);
+ updateMemoryUsagePerPackageLocked(oldState.packageName, newSize);
+
addHistoricalOperationLocked(HISTORICAL_OPERATION_DELETE, oldState);
scheduleWriteIfNeededLocked();
@@ -380,16 +388,18 @@ final class SettingsState {
Setting oldSetting = new Setting(setting);
String oldValue = setting.getValue();
String oldDefaultValue = setting.getDefaultValue();
+ String newValue = oldDefaultValue;
+ String newDefaultValue = oldDefaultValue;
+
+ int newSize = getNewMemoryUsagePerPackageLocked(setting.packageName, oldValue,
+ newValue, oldDefaultValue, newDefaultValue);
+ checkNewMemoryUsagePerPackageLocked(setting.packageName, newSize);
if (!setting.reset()) {
return false;
}
- String newValue = setting.getValue();
- String newDefaultValue = setting.getDefaultValue();
-
- updateMemoryUsagePerPackageLocked(setting.packageName, oldValue,
- newValue, oldDefaultValue, newDefaultValue);
+ updateMemoryUsagePerPackageLocked(setting.packageName, newSize);
addHistoricalOperationLocked(HISTORICAL_OPERATION_RESET, oldSetting);
@@ -492,38 +502,49 @@ final class SettingsState {
}
}
- private void updateMemoryUsagePerPackageLocked(String packageName, String oldValue,
- String newValue, String oldDefaultValue, String newDefaultValue) {
- if (mMaxBytesPerAppPackage == MAX_BYTES_PER_APP_PACKAGE_UNLIMITED) {
- return;
- }
+ private boolean isExemptFromMemoryUsageCap(String packageName) {
+ return mMaxBytesPerAppPackage == MAX_BYTES_PER_APP_PACKAGE_UNLIMITED
+ || SYSTEM_PACKAGE_NAME.equals(packageName);
+ }
- if (SYSTEM_PACKAGE_NAME.equals(packageName)) {
+ @GuardedBy("mLock")
+ private void checkNewMemoryUsagePerPackageLocked(String packageName, int newSize)
+ throws IllegalStateException {
+ if (isExemptFromMemoryUsageCap(packageName)) {
return;
}
+ if (newSize > mMaxBytesPerAppPackage) {
+ throw new IllegalStateException("You are adding too many system settings. "
+ + "You should stop using system settings for app specific data"
+ + " package: " + packageName);
+ }
+ }
+ @GuardedBy("mLock")
+ private int getNewMemoryUsagePerPackageLocked(String packageName, String oldValue,
+ String newValue, String oldDefaultValue, String newDefaultValue) {
+ if (isExemptFromMemoryUsageCap(packageName)) {
+ return 0;
+ }
+ final Integer currentSize = mPackageToMemoryUsage.get(packageName);
final int oldValueSize = (oldValue != null) ? oldValue.length() : 0;
final int newValueSize = (newValue != null) ? newValue.length() : 0;
final int oldDefaultValueSize = (oldDefaultValue != null) ? oldDefaultValue.length() : 0;
final int newDefaultValueSize = (newDefaultValue != null) ? newDefaultValue.length() : 0;
final int deltaSize = newValueSize + newDefaultValueSize
- oldValueSize - oldDefaultValueSize;
+ return Math.max((currentSize != null) ? currentSize + deltaSize : deltaSize, 0);
+ }
- Integer currentSize = mPackageToMemoryUsage.get(packageName);
- final int newSize = Math.max((currentSize != null)
- ? currentSize + deltaSize : deltaSize, 0);
-
- if (newSize > mMaxBytesPerAppPackage) {
- throw new IllegalStateException("You are adding too many system settings. "
- + "You should stop using system settings for app specific data"
- + " package: " + packageName);
+ @GuardedBy("mLock")
+ private void updateMemoryUsagePerPackageLocked(String packageName, int newSize) {
+ if (isExemptFromMemoryUsageCap(packageName)) {
+ return;
}
-
if (DEBUG) {
Slog.i(LOG_TAG, "Settings for package: " + packageName
+ " size: " + newSize + " bytes.");
}
-
mPackageToMemoryUsage.put(packageName, newSize);
}
diff --git a/packages/SettingsProvider/test/src/com/android/providers/settings/SettingsStateTest.java b/packages/SettingsProvider/test/src/com/android/providers/settings/SettingsStateTest.java
index 3f68554ffe87..6f45adef91f7 100644
--- a/packages/SettingsProvider/test/src/com/android/providers/settings/SettingsStateTest.java
+++ b/packages/SettingsProvider/test/src/com/android/providers/settings/SettingsStateTest.java
@@ -21,6 +21,8 @@ import android.util.Xml;
import org.xmlpull.v1.XmlSerializer;
+import com.google.common.base.Strings;
+
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
@@ -46,7 +48,6 @@ public class SettingsStateTest extends AndroidTestCase {
"\uD800ab\uDC00 " + // broken surrogate pairs
"日本語";
-
public void testIsBinary() {
assertFalse(SettingsState.isBinary(" abc 日本語"));
@@ -182,4 +183,44 @@ public class SettingsStateTest extends AndroidTestCase {
assertEquals("p2", s.getPackageName());
}
}
+
+ public void testInsertSetting_memoryUsage() {
+ final Object lock = new Object();
+ final File file = new File(getContext().getCacheDir(), "setting.xml");
+ final String settingName = "test_setting";
+
+ SettingsState settingsState = new SettingsState(getContext(), lock, file, 1,
+ SettingsState.MAX_BYTES_PER_APP_PACKAGE_UNLIMITED, Looper.getMainLooper());
+ // No exception should be thrown when there is no cap
+ settingsState.insertSettingLocked(settingName, Strings.repeat("A", 20001),
+ null, false, "p1");
+ settingsState.deleteSettingLocked(settingName);
+
+ settingsState = new SettingsState(getContext(), lock, file, 1,
+ SettingsState.MAX_BYTES_PER_APP_PACKAGE_LIMITED, Looper.getMainLooper());
+ // System package doesn't have memory usage limit
+ settingsState.insertSettingLocked(settingName, Strings.repeat("A", 20001),
+ null, false, "android");
+ settingsState.deleteSettingLocked(settingName);
+
+ // Should not throw if usage is under the cap
+ settingsState.insertSettingLocked(settingName, Strings.repeat("A", 19999),
+ null, false, "p1");
+ settingsState.deleteSettingLocked(settingName);
+ try {
+ settingsState.insertSettingLocked(settingName, Strings.repeat("A", 20001),
+ null, false, "p1");
+ fail("Should throw because it exceeded per package memory usage");
+ } catch (IllegalStateException ex) {
+ assertTrue(ex.getMessage().contains("p1"));
+ }
+ try {
+ settingsState.insertSettingLocked(settingName, Strings.repeat("A", 20001),
+ null, false, "p1");
+ fail("Should throw because it exceeded per package memory usage");
+ } catch (IllegalStateException ex) {
+ assertTrue(ex.getMessage().contains("p1"));
+ }
+ assertTrue(settingsState.getSettingLocked(settingName).isNull());
+ }
}