Crash occurring when using Intune with Realm Java SDK

[sandeep-kumar-eptura]

How frequently does the bug occur?

Always

Description

Android: SIGSEGV with Realm 10.19.0 when Microsoft Intune MAM “Encrypt org data” policy is Required

Upgrading Realm Java from 10.17.0 to 10.19.0 causes a native crash (SIGSEGV, SEGV_ACCERR) on Android when Microsoft Intune MAM policy “Encrypt org data” is set to Require. The same app, same policy, same Intune MAM SDK works fine on Realm 10.17.0. Appears related to changes in Realm Core’s mmap/protection behavior between 10.17.x and 10.19.0.

Related issue posted on intune sdk : microsoftconnect/ms-intune-app-sdk-android#253

Environment

Realm Java: 10.19.0
Intune MAM SDK (Android): 12.0.2 (16KB page-size not compatible).
Android: target/compile SDK 35–36, minSdk 29
Kotlin: 2.0.x
RxJava3

Policies (Intune)

Encrypt org data: Require
Encrypt org data on enrolled devices: Require

Configuration snippet

Minimal Realm setup (project uses Realm encryption; same config works on 10.17.0):

val key: ByteArray = /* app-provided 64 bytes total, e.g. two concatenated 32-byte keys */
Realm.init(context)
val config = RealmConfiguration.Builder()
    .encryptionKey(key)
    .name("app.realm")
    .schemaVersion(18L)
    .migration(Migrations())
    .build()
Realm.setDefaultConfiguration(config)

Stacktrace & log output

Fatal signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0xXXXXXXXXXXXX in tid NNNNN (RxCachedThreadS), pid PPPPP


Non-fatal Exception: io.realm.exceptions.RealmFileException: Failed to open Realm file at path '/data/user/0/com.condecosoftware.condeco.develop/files/condecounified.realm': Realm file decryption failed (Decryption failed: 'unable to decrypt after 0 seconds (retry_count=4, from=i != bytes_read, size=4096)') (/data/user/0/com.condecosoftware.condeco.develop/files/condecounified.realm) in /tmp/realm-java/realm/realm-library/src/main/cpp/io_realm_internal_OsSharedRealm.cpp line 107
       at io.realm.internal.OsSharedRealm.nativeGetSharedRealm(OsSharedRealm.java)
       at io.realm.internal.OsSharedRealm.<init>(OsSharedRealm.java:175)
       at io.realm.internal.OsSharedRealm.getInstance(OsSharedRealm.java:260)
       at io.realm.BaseRealm.<init>(BaseRealm.java:142)
       at io.realm.BaseRealm.<init>(BaseRealm.java:109)
       at io.realm.Realm.<init>(Realm.java:161)
       at io.realm.Realm.createInstance(Realm.java:535)
       at io.realm.RealmCache.createInstance(RealmCache.java:508)
       at io.realm.RealmCache.doCreateRealmOrGetFromCache(RealmCache.java:461)
       at io.realm.RealmCache.createRealmOrGetFromCache(RealmCache.java:422)
       at io.realm.Realm.getDefaultInstance(Realm.java:443)
       at com.condecosoftware.condeco.storage.realm.AndroidRealm$get$1.apply(AndroidRealm.kt:71)
       at com.condecosoftware.condeco.storage.realm.AndroidRealm$get$1.apply(AndroidRealm.kt:70)
       at io.reactivex.rxjava3.internal.operators.observable.ObservableMap$MapObserver.onNext(ObservableMap.java:58)
       at io.reactivex.rxjava3.internal.operators.observable.ObservableScalarXMap$ScalarDisposable.run(ObservableScalarXMap.java:248)
       at io.reactivex.rxjava3.internal.operators.observable.ObservableJust.subscribeActual(ObservableJust.java:35)
       at io.reactivex.rxjava3.core.Observable.subscribe(Observable.java:13173)
       at io.reactivex.rxjava3.internal.operators.observable.ObservableMap.subscribeActual(ObservableMap.java:33)
       at io.reactivex.rxjava3.core.Observable.subscribe(Observable.java:13173)
       at io.reactivex.rxjava3.internal.operators.observable.ObservableSubscribeOn$SubscribeTask.run(ObservableSubscribeOn.java:96)
       at io.reactivex.rxjava3.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:123)
       at android.os.Handler.handleCallback(Handler.java:995)
       at android.os.Handler.dispatchMessage(Handler.java:103)
       at android.os.Looper.loopOnce(Looper.java:273)
       at android.os.Looper.loop(Looper.java:363)
       at android.os.HandlerThread.run(HandlerThread.java:85)
        

Can you reproduce the bug?

Always

Reproduction Steps

1. Integrate Microsoft Intune MAM SDK (12.0.2) in an Android app.
2. Set Intune policy “Encrypt org data” to Require (and Require on enrolled devices).
3. Use Realm Java 10.19.0 with an encrypted Realm as shown above.
4. Launch the app and perform typical DB reads/writes (on background thread, Realm’s own HandlerThread).
5. App crashes with SIGSEGV.
6. With Realm Java 10.17.0 and the same policy + SDK, the app runs without crash.

Expected Behavior

No crash. Realm should work with MAM “Encrypt org data” policy enabled, as it does on 10.17.0.

Version

10.19.0

What Atlas App Services are you using?

-- select --

Are you using encryption?

Yes

Platform OS and version(s)

Android

Build environment

• Android Studio version:
  Android Studio Otter | 2025.2.1 Patch 1
  Build #AI-252.25557.131.2521.14432022, built on November 13, 2025
  Runtime version: 21.0.8+-14196175-b1038.72 aarch64
  VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
  Toolkit: sun.lwawt.macosx.LWCToolkit
  macOS 26.1
  GC: G1 Young Generation, G1 Concurrent GC, G1 Old Generation
  Memory: 8192M
  Cores: 14
  Metal Rendering is ON
  Registry:
  ide.instant.shutdown=false
  com.android.studio.ml.activeModel=com.android.studio.ml.AidaModel
  Non-Bundled Plugins:
  com.intellij.classic.ui (252.23892.201)
  com.github.copilot (1.5.61-243)

• Android Build Tools version: 35.0.0

• Gradle version: 8.13 (Android Gradle Plugin 8.13.0)

If useful:

• Kotlin: 2.0.21
• compileSdk: 35 (app module)
• NDK: 27.1.12297006

[sandeep-kumar-eptura]

posted same on https://x.com/KumarSande49496/status/1993328719193424006?s=20