Only accept binary name not path

I think we've discussed this a couple of times, although I can't now
find a link.

There's really no reason to specify a path, it's complicated to
describe, and it might open up weird path traversal attacks,so
disallow it.

Rename setPayloadBinaryPath to setPayloadBinaryName to reflect this
(and rename lots of other things to match). Add a check that it isn't
a path, and a test for that (and fix some other tests that were
breaking the new rule).

Also expand on the Javadoc around ABI & 32/64-bit.

Also add a check inside VS (because checks in the payload code can be
bypassed), and a host test for that.

Note that a VM created with a config file can still specify a path
inside the config file; CompOS relies on that to run code from its
APEX.

Bug: 261037705
Test: atest MicrodroidTests MicrodroidHostTests
Change-Id: Ie59b9c81d13a7a3e4ec62cf874d43bfaf6163431
diff --git a/demo/java/com/android/microdroid/demo/MainActivity.java b/demo/java/com/android/microdroid/demo/MainActivity.java
index 54d7420..c3fa55f 100644
--- a/demo/java/com/android/microdroid/demo/MainActivity.java
+++ b/demo/java/com/android/microdroid/demo/MainActivity.java
@@ -19,7 +19,6 @@
 import android.app.Application;
 import android.os.Bundle;
 import android.os.IBinder;
-import android.os.ParcelFileDescriptor;
 import android.os.RemoteException;
 import android.system.virtualmachine.VirtualMachine;
 import android.system.virtualmachine.VirtualMachineCallback;
@@ -243,7 +242,7 @@
             try {
                 VirtualMachineConfig.Builder builder =
                         new VirtualMachineConfig.Builder(getApplication());
-                builder.setPayloadBinaryPath("MicrodroidTestNativeLib.so");
+                builder.setPayloadBinaryName("MicrodroidTestNativeLib.so");
                 builder.setProtectedVm(true);
                 if (debug) {
                     builder.setDebugLevel(VirtualMachineConfig.DEBUG_LEVEL_FULL);
diff --git a/javalib/api/system-current.txt b/javalib/api/system-current.txt
index 30e437b..71bdf13 100644
--- a/javalib/api/system-current.txt
+++ b/javalib/api/system-current.txt
@@ -61,7 +61,7 @@
     method @IntRange(from=0) public long getEncryptedStorageKib();
     method @IntRange(from=0) public int getMemoryMib();
     method @IntRange(from=1) public int getNumCpus();
-    method @Nullable public String getPayloadBinaryPath();
+    method @Nullable public String getPayloadBinaryName();
     method public boolean isCompatibleWith(@NonNull android.system.virtualmachine.VirtualMachineConfig);
     method public boolean isEncryptedStorageEnabled();
     method public boolean isProtectedVm();
@@ -77,7 +77,7 @@
     method @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setEncryptedStorageKib(@IntRange(from=1) long);
     method @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setMemoryMib(@IntRange(from=1) int);
     method @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setNumCpus(@IntRange(from=1) int);
-    method @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setPayloadBinaryPath(@NonNull String);
+    method @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setPayloadBinaryName(@NonNull String);
     method @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setProtectedVm(boolean);
   }
 
diff --git a/javalib/src/android/system/virtualmachine/VirtualMachine.java b/javalib/src/android/system/virtualmachine/VirtualMachine.java
index 34851e4..e319aa3 100644
--- a/javalib/src/android/system/virtualmachine/VirtualMachine.java
+++ b/javalib/src/android/system/virtualmachine/VirtualMachine.java
@@ -1226,17 +1226,15 @@
     public String toString() {
         VirtualMachineConfig config = getConfig();
         String payloadConfigPath = config.getPayloadConfigPath();
-        String payloadBinaryPath = config.getPayloadBinaryPath();
+        String payloadBinaryName = config.getPayloadBinaryName();
 
         StringBuilder result = new StringBuilder();
         result.append("VirtualMachine(")
                 .append("name:")
                 .append(getName())
                 .append(", ");
-        if (payloadBinaryPath != null) {
-            result.append("payload:")
-                    .append(payloadBinaryPath)
-                    .append(", ");
+        if (payloadBinaryName != null) {
+            result.append("payload:").append(payloadBinaryName).append(", ");
         }
         if (payloadConfigPath != null) {
             result.append("config:")
diff --git a/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java b/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
index 7c16798..0e9e86b 100644
--- a/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
+++ b/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
@@ -62,7 +62,7 @@
     private static final String KEY_VERSION = "version";
     private static final String KEY_APKPATH = "apkPath";
     private static final String KEY_PAYLOADCONFIGPATH = "payloadConfigPath";
-    private static final String KEY_PAYLOADBINARYPATH = "payloadBinaryPath";
+    private static final String KEY_PAYLOADBINARYNAME = "payloadBinaryPath";
     private static final String KEY_DEBUGLEVEL = "debugLevel";
     private static final String KEY_PROTECTED_VM = "protectedVm";
     private static final String KEY_MEMORY_MIB = "memoryMib";
@@ -118,10 +118,8 @@
      */
     @Nullable private final String mPayloadConfigPath;
 
-    /**
-     * Path within the APK to the payload binary file that will be executed within the VM.
-     */
-    @Nullable private final String mPayloadBinaryPath;
+    /** Name of the payload binary file within the APK that will be executed within the VM. */
+    @Nullable private final String mPayloadBinaryName;
 
     /** The size of storage in KiB. 0 indicates that encryptedStorage is not required */
     private final long mEncryptedStorageKib;
@@ -129,7 +127,7 @@
     private VirtualMachineConfig(
             @NonNull String apkPath,
             @Nullable String payloadConfigPath,
-            @Nullable String payloadBinaryPath,
+            @Nullable String payloadBinaryName,
             @DebugLevel int debugLevel,
             boolean protectedVm,
             int memoryMib,
@@ -138,7 +136,7 @@
         // This is only called from Builder.build(); the builder handles parameter validation.
         mApkPath = apkPath;
         mPayloadConfigPath = payloadConfigPath;
-        mPayloadBinaryPath = payloadBinaryPath;
+        mPayloadBinaryName = payloadBinaryName;
         mDebugLevel = debugLevel;
         mProtectedVm = protectedVm;
         mMemoryMib = memoryMib;
@@ -192,7 +190,7 @@
 
         String payloadConfigPath = b.getString(KEY_PAYLOADCONFIGPATH);
         if (payloadConfigPath == null) {
-            builder.setPayloadBinaryPath(b.getString(KEY_PAYLOADBINARYPATH));
+            builder.setPayloadBinaryName(b.getString(KEY_PAYLOADBINARYNAME));
         } else {
             builder.setPayloadConfigPath(payloadConfigPath);
         }
@@ -231,7 +229,7 @@
         b.putInt(KEY_VERSION, VERSION);
         b.putString(KEY_APKPATH, mApkPath);
         b.putString(KEY_PAYLOADCONFIGPATH, mPayloadConfigPath);
-        b.putString(KEY_PAYLOADBINARYPATH, mPayloadBinaryPath);
+        b.putString(KEY_PAYLOADBINARYNAME, mPayloadBinaryName);
         b.putInt(KEY_DEBUGLEVEL, mDebugLevel);
         b.putBoolean(KEY_PROTECTED_VM, mProtectedVm);
         b.putInt(KEY_NUM_CPUS, mNumCpus);
@@ -269,15 +267,15 @@
     }
 
     /**
-     * Returns the path within the {@code lib/<ABI>} directory of the APK to the payload binary file
+     * Returns the name of the payload binary file, in the {@code lib/<ABI>} directory of the APK,
      * that will be executed within the VM.
      *
      * @hide
      */
     @SystemApi
     @Nullable
-    public String getPayloadBinaryPath() {
-        return mPayloadBinaryPath;
+    public String getPayloadBinaryName() {
+        return mPayloadBinaryName;
     }
 
     /**
@@ -362,7 +360,7 @@
                 && this.mProtectedVm == other.mProtectedVm
                 && this.mEncryptedStorageKib == other.mEncryptedStorageKib
                 && Objects.equals(this.mPayloadConfigPath, other.mPayloadConfigPath)
-                && Objects.equals(this.mPayloadBinaryPath, other.mPayloadBinaryPath)
+                && Objects.equals(this.mPayloadBinaryName, other.mPayloadBinaryName)
                 && this.mApkPath.equals(other.mApkPath);
     }
 
@@ -376,9 +374,9 @@
     VirtualMachineAppConfig toVsConfig() throws FileNotFoundException {
         VirtualMachineAppConfig vsConfig = new VirtualMachineAppConfig();
         vsConfig.apk = ParcelFileDescriptor.open(new File(mApkPath), MODE_READ_ONLY);
-        if (mPayloadBinaryPath != null) {
+        if (mPayloadBinaryName != null) {
             VirtualMachinePayloadConfig payloadConfig = new VirtualMachinePayloadConfig();
-            payloadConfig.payloadPath = mPayloadBinaryPath;
+            payloadConfig.payloadBinaryName = mPayloadBinaryName;
             vsConfig.payload =
                     VirtualMachineAppConfig.Payload.payloadConfig(payloadConfig);
         } else {
@@ -411,7 +409,7 @@
         @Nullable private final Context mContext;
         @Nullable private String mApkPath;
         @Nullable private String mPayloadConfigPath;
-        @Nullable private String mPayloadBinaryPath;
+        @Nullable private String mPayloadBinaryName;
         @DebugLevel private int mDebugLevel = DEBUG_LEVEL_NONE;
         private boolean mProtectedVm;
         private boolean mProtectedVmSet;
@@ -455,14 +453,14 @@
                 apkPath = mApkPath;
             }
 
-            if (mPayloadBinaryPath == null) {
+            if (mPayloadBinaryName == null) {
                 if (mPayloadConfigPath == null) {
-                    throw new IllegalStateException("setPayloadBinaryPath must be called");
+                    throw new IllegalStateException("setPayloadBinaryName must be called");
                 }
             } else {
                 if (mPayloadConfigPath != null) {
                     throw new IllegalStateException(
-                            "setPayloadBinaryPath and setPayloadConfigPath may not both be called");
+                            "setPayloadBinaryName and setPayloadConfigPath may not both be called");
                 }
             }
 
@@ -473,7 +471,7 @@
             return new VirtualMachineConfig(
                     apkPath,
                     mPayloadConfigPath,
-                    mPayloadBinaryPath,
+                    mPayloadBinaryName,
                     mDebugLevel,
                     mProtectedVm,
                     mMemoryMib,
@@ -515,16 +513,23 @@
         }
 
         /**
-         * Sets the path within the {@code lib/<ABI>} directory of the APK to the payload binary
-         * file that will be executed within the VM.
+         * Sets the name of the payload binary file that will be executed within the VM, e.g.
+         * "payload.so". The file must reside in the {@code lib/<ABI>} directory of the APK.
+         *
+         * <p>Note that VMs only support 64-bit code, even if the owning app is running as a 32-bit
+         * process.
          *
          * @hide
          */
         @SystemApi
         @NonNull
-        public Builder setPayloadBinaryPath(@NonNull String payloadBinaryPath) {
-            mPayloadBinaryPath =
-                    requireNonNull(payloadBinaryPath, "payloadBinaryPath must not be null");
+        public Builder setPayloadBinaryName(@NonNull String payloadBinaryName) {
+            if (payloadBinaryName.contains(File.separator)) {
+                throw new IllegalArgumentException(
+                        "Invalid binary file name: " + payloadBinaryName);
+            }
+            mPayloadBinaryName =
+                    requireNonNull(payloadBinaryName, "payloadBinaryName must not be null");
             return this;
         }
 
diff --git a/microdroid/payload/metadata.proto b/microdroid/payload/metadata.proto
index 1d8dd8c..c74c23b 100644
--- a/microdroid/payload/metadata.proto
+++ b/microdroid/payload/metadata.proto
@@ -65,6 +65,6 @@
 
 message PayloadConfig {
   // Required.
-  // Path to the payload binary file inside the APK.
-  string payload_binary_path = 1;
+  // Name of the payload binary file inside the APK.
+  string payload_binary_name = 1;
 }
diff --git a/microdroid_manager/src/main.rs b/microdroid_manager/src/main.rs
index 4018d00..b237bab 100644
--- a/microdroid_manager/src/main.rs
+++ b/microdroid_manager/src/main.rs
@@ -259,7 +259,7 @@
     //   ? -71001: PayloadConfig
     // }
     // PayloadConfig = {
-    //   1: tstr // payload_binary_path
+    //   1: tstr // payload_binary_name
     // }
 
     let mut config_desc = vec![
@@ -278,7 +278,7 @@
             encode_negative_number(-71001, &mut config_desc)?;
             encode_header(5, 1, &mut config_desc)?; // map(1)
             encode_number(1, &mut config_desc)?;
-            encode_tstr(&payload_config.payload_binary_path, &mut config_desc)?;
+            encode_tstr(&payload_config.payload_binary_name, &mut config_desc)?;
         }
     }
 
@@ -757,7 +757,7 @@
         PayloadMetadata::config(payload_config) => {
             let task = Task {
                 type_: TaskType::MicrodroidLauncher,
-                command: payload_config.payload_binary_path,
+                command: payload_config.payload_binary_name,
             };
             Ok(VmPayloadConfig {
                 os: OsConfig { name: "microdroid".to_owned() },
diff --git a/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java b/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
index 9cfac4e..9e4b228 100644
--- a/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
+++ b/tests/benchmark/src/java/com/android/microdroid/benchmark/MicrodroidBenchmarks.java
@@ -93,7 +93,7 @@
             throws VirtualMachineException, InterruptedException, IOException {
         VirtualMachineConfig normalConfig =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidIdleNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidIdleNativeLib.so")
                         .setDebugLevel(DEBUG_LEVEL_NONE)
                         .setMemoryMib(mem)
                         .build();
@@ -146,7 +146,7 @@
         for (int i = 0; i < trialCount; i++) {
             VirtualMachineConfig normalConfig =
                     newVmConfigBuilder()
-                            .setPayloadBinaryPath("MicrodroidIdleNativeLib.so")
+                            .setPayloadBinaryName("MicrodroidIdleNativeLib.so")
                             .setDebugLevel(DEBUG_LEVEL_NONE)
                             .setMemoryMib(256)
                             .build();
@@ -174,7 +174,7 @@
             for (int i = 0; i < trialCount; i++) {
                 VirtualMachineConfig normalConfig =
                         newVmConfigBuilder()
-                                .setPayloadBinaryPath("MicrodroidIdleNativeLib.so")
+                                .setPayloadBinaryName("MicrodroidIdleNativeLib.so")
                                 .setDebugLevel(DEBUG_LEVEL_NONE)
                                 .setMemoryMib(256)
                                 .setNumCpus(numCpus)
@@ -209,7 +209,7 @@
             // To grab boot events from log, set debug mode to FULL
             VirtualMachineConfig normalConfig =
                     newVmConfigBuilder()
-                            .setPayloadBinaryPath("MicrodroidIdleNativeLib.so")
+                            .setPayloadBinaryName("MicrodroidIdleNativeLib.so")
                             .setDebugLevel(DEBUG_LEVEL_FULL)
                             .setMemoryMib(256)
                             .build();
diff --git a/tests/hostside/java/com/android/microdroid/test/MicrodroidHostTests.java b/tests/hostside/java/com/android/microdroid/test/MicrodroidHostTests.java
index e02f85f..157a03f 100644
--- a/tests/hostside/java/com/android/microdroid/test/MicrodroidHostTests.java
+++ b/tests/hostside/java/com/android/microdroid/test/MicrodroidHostTests.java
@@ -795,6 +795,39 @@
                                 + " permission");
     }
 
+    @Test
+    public void testPathToBinaryIsRejected() throws Exception {
+        CommandRunner android = new CommandRunner(getDevice());
+
+        // Create the idsig file for the APK
+        final String apkPath = getPathForPackage(PACKAGE_NAME);
+        final String idSigPath = TEST_ROOT + "idsig";
+        android.run(VIRT_APEX + "bin/vm", "create-idsig", apkPath, idSigPath);
+
+        // Create the instance image for the VM
+        final String instanceImgPath = TEST_ROOT + "instance.img";
+        android.run(
+                VIRT_APEX + "bin/vm",
+                "create-partition",
+                "--type instance",
+                instanceImgPath,
+                Integer.toString(10 * 1024 * 1024));
+
+        final String ret =
+                android.runForResult(
+                                VIRT_APEX + "bin/vm",
+                                "run-app",
+                                "--payload-binary-name",
+                                "./MicrodroidTestNativeLib.so",
+                                apkPath,
+                                idSigPath,
+                                instanceImgPath)
+                        .getStderr()
+                        .trim();
+
+        assertThat(ret).contains("Payload binary name must not specify a path");
+    }
+
     @Before
     public void setUp() throws Exception {
         testIfDeviceIsCapable(getDevice());
diff --git a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
index 2656c3b..b206056 100644
--- a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
+++ b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
@@ -126,7 +126,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .build();
@@ -150,7 +150,7 @@
         // But we do need non-debug VMs to work, so run one.
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setDebugLevel(DEBUG_LEVEL_NONE)
                         .build();
@@ -174,7 +174,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .build();
 
@@ -193,7 +193,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .build();
@@ -224,7 +224,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .build();
@@ -273,7 +273,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .build();
@@ -321,13 +321,13 @@
     public void vmConfigGetAndSetTests() {
         // Minimal has as little as specified as possible; everything that can be is defaulted.
         VirtualMachineConfig.Builder minimalBuilder = newVmConfigBuilder();
-        VirtualMachineConfig minimal = minimalBuilder.setPayloadBinaryPath("binary/path").build();
+        VirtualMachineConfig minimal = minimalBuilder.setPayloadBinaryName("binary.so").build();
 
         assertThat(minimal.getApkPath()).isEqualTo(getContext().getPackageCodePath());
         assertThat(minimal.getDebugLevel()).isEqualTo(DEBUG_LEVEL_NONE);
         assertThat(minimal.getMemoryMib()).isEqualTo(0);
         assertThat(minimal.getNumCpus()).isEqualTo(1);
-        assertThat(minimal.getPayloadBinaryPath()).isEqualTo("binary/path");
+        assertThat(minimal.getPayloadBinaryName()).isEqualTo("binary.so");
         assertThat(minimal.getPayloadConfigPath()).isNull();
         assertThat(minimal.isProtectedVm()).isEqualTo(isProtectedVm());
         assertThat(minimal.isEncryptedStorageEnabled()).isFalse();
@@ -350,7 +350,7 @@
         assertThat(maximal.getDebugLevel()).isEqualTo(DEBUG_LEVEL_FULL);
         assertThat(maximal.getMemoryMib()).isEqualTo(42);
         assertThat(maximal.getNumCpus()).isEqualTo(maxCpus);
-        assertThat(maximal.getPayloadBinaryPath()).isNull();
+        assertThat(maximal.getPayloadBinaryName()).isNull();
         assertThat(maximal.getPayloadConfigPath()).isEqualTo("config/path");
         assertThat(maximal.isProtectedVm()).isEqualTo(isProtectedVm());
         assertThat(maximal.isEncryptedStorageEnabled()).isTrue();
@@ -370,12 +370,14 @@
         assertThrows(NullPointerException.class, () -> new VirtualMachineConfig.Builder(null));
         assertThrows(NullPointerException.class, () -> builder.setApkPath(null));
         assertThrows(NullPointerException.class, () -> builder.setPayloadConfigPath(null));
-        assertThrows(NullPointerException.class, () -> builder.setPayloadBinaryPath(null));
+        assertThrows(NullPointerException.class, () -> builder.setPayloadBinaryName(null));
         assertThrows(NullPointerException.class, () -> builder.setPayloadConfigPath(null));
 
         // Individual property checks.
         assertThrows(
                 IllegalArgumentException.class, () -> builder.setApkPath("relative/path/to.apk"));
+        assertThrows(
+                IllegalArgumentException.class, () -> builder.setPayloadBinaryName("dir/file.so"));
         assertThrows(IllegalArgumentException.class, () -> builder.setDebugLevel(-1));
         assertThrows(IllegalArgumentException.class, () -> builder.setMemoryMib(0));
         assertThrows(IllegalArgumentException.class, () -> builder.setNumCpus(0));
@@ -384,10 +386,10 @@
         // Consistency checks enforced at build time.
         Exception e;
         e = assertThrows(IllegalStateException.class, () -> builder.build());
-        assertThat(e).hasMessageThat().contains("setPayloadBinaryPath must be called");
+        assertThat(e).hasMessageThat().contains("setPayloadBinaryName must be called");
 
         VirtualMachineConfig.Builder protectedNotSet =
-                new VirtualMachineConfig.Builder(getContext()).setPayloadBinaryPath("binary/path");
+                new VirtualMachineConfig.Builder(getContext()).setPayloadBinaryName("binary.so");
         e = assertThrows(IllegalStateException.class, () -> protectedNotSet.build());
         assertThat(e).hasMessageThat().contains("setProtectedVm must be called");
     }
@@ -398,7 +400,7 @@
         int maxCpus = Runtime.getRuntime().availableProcessors();
 
         VirtualMachineConfig.Builder builder =
-                newVmConfigBuilder().setPayloadBinaryPath("binary/path").setApkPath("/apk/path");
+                newVmConfigBuilder().setPayloadBinaryName("binary.so").setApkPath("/apk/path");
         VirtualMachineConfig baseline = builder.build();
 
         // A config must be compatible with itself
@@ -412,7 +414,7 @@
 
         // Changes that must be incompatible, since they must change the VM identity.
         assertConfigCompatible(baseline, builder.setDebugLevel(DEBUG_LEVEL_FULL)).isFalse();
-        assertConfigCompatible(baseline, builder.setPayloadBinaryPath("different")).isFalse();
+        assertConfigCompatible(baseline, builder.setPayloadBinaryName("different")).isFalse();
         int capabilities = getVirtualMachineManager().getCapabilities();
         if ((capabilities & CAPABILITY_PROTECTED_VM) != 0
                 && (capabilities & CAPABILITY_NON_PROTECTED_VM) != 0) {
@@ -434,19 +436,19 @@
     @CddTest(requirements = {"9.17/C-1-1"})
     public void vmUnitTests() throws Exception {
         VirtualMachineConfig.Builder builder =
-                newVmConfigBuilder().setPayloadBinaryPath("binary/path");
+                newVmConfigBuilder().setPayloadBinaryName("binary.so");
         VirtualMachineConfig config = builder.build();
         VirtualMachine vm = forceCreateNewVirtualMachine("vm_name", config);
 
         assertThat(vm.getName()).isEqualTo("vm_name");
-        assertThat(vm.getConfig().getPayloadBinaryPath()).isEqualTo("binary/path");
+        assertThat(vm.getConfig().getPayloadBinaryName()).isEqualTo("binary.so");
         assertThat(vm.getConfig().getMemoryMib()).isEqualTo(0);
 
         VirtualMachineConfig compatibleConfig = builder.setMemoryMib(42).build();
         vm.setConfig(compatibleConfig);
 
         assertThat(vm.getName()).isEqualTo("vm_name");
-        assertThat(vm.getConfig().getPayloadBinaryPath()).isEqualTo("binary/path");
+        assertThat(vm.getConfig().getPayloadBinaryName()).isEqualTo("binary.so");
         assertThat(vm.getConfig().getMemoryMib()).isEqualTo(42);
 
         assertThat(getVirtualMachineManager().get("vm_name")).isSameInstanceAs(vm);
@@ -459,7 +461,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .build();
@@ -507,7 +509,7 @@
         final int userId = ctx.getUserId();
         final VirtualMachineManager vmm = ctx.getSystemService(VirtualMachineManager.class);
         VirtualMachineConfig config =
-                newVmConfigBuilder().setPayloadBinaryPath("binary/path").build();
+                newVmConfigBuilder().setPayloadBinaryName("binary.so").build();
         try {
             VirtualMachine vm = vmm.create("vm-name", config);
             // TODO(b/261430346): what about non-primary user?
@@ -526,7 +528,7 @@
         final int userId = ctx.getUserId();
         final VirtualMachineManager vmm = ctx.getSystemService(VirtualMachineManager.class);
         VirtualMachineConfig config =
-                newVmConfigBuilder().setPayloadBinaryPath("binary/path").build();
+                newVmConfigBuilder().setPayloadBinaryName("binary.so").build();
         try {
             VirtualMachine vm = vmm.create("vm-name", config);
             // TODO(b/261430346): what about non-primary user?
@@ -578,7 +580,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .build();
 
@@ -605,7 +607,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setApkPath(getContext().getPackageCodePath())
                         .setMemoryMib(minMemoryRequired())
                         .setDebugLevel(DEBUG_LEVEL_FULL)
@@ -651,7 +653,7 @@
         for (int memMib : new int[]{ 10, 20, 40 }) {
             VirtualMachineConfig lowMemConfig =
                     newVmConfigBuilder()
-                            .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                            .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                             .setMemoryMib(memMib)
                             .setDebugLevel(DEBUG_LEVEL_NONE)
                             .build();
@@ -695,7 +697,7 @@
 
         VirtualMachineConfig.Builder builder =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setDebugLevel(fromLevel);
         VirtualMachineConfig normalConfig = builder.build();
         forceCreateNewVirtualMachine("test_vm", normalConfig);
@@ -865,7 +867,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .build();
         forceCreateNewVirtualMachine("test_vm", config);
@@ -912,7 +914,7 @@
     private RandomAccessFile prepareInstanceImage(String vmName) throws Exception {
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .build();
 
@@ -985,9 +987,9 @@
     }
 
     @Test
-    public void bootFailsWhenBinaryPathIsInvalid() throws Exception {
+    public void bootFailsWhenBinaryNameIsInvalid() throws Exception {
         VirtualMachineConfig.Builder builder =
-                newVmConfigBuilder().setPayloadBinaryPath("DoesNotExist.so");
+                newVmConfigBuilder().setPayloadBinaryName("DoesNotExist.so");
         VirtualMachineConfig normalConfig = builder.setDebugLevel(DEBUG_LEVEL_FULL).build();
         forceCreateNewVirtualMachine("test_vm_invalid_binary_path", normalConfig);
 
@@ -1024,7 +1026,7 @@
     @Test
     public void bootFailsWhenBinaryIsMissingEntryFunction() throws Exception {
         VirtualMachineConfig.Builder builder =
-                newVmConfigBuilder().setPayloadBinaryPath("MicrodroidEmptyNativeLib.so");
+                newVmConfigBuilder().setPayloadBinaryName("MicrodroidEmptyNativeLib.so");
         VirtualMachineConfig normalConfig = builder.setDebugLevel(DEBUG_LEVEL_FULL).build();
         VirtualMachine vm = forceCreateNewVirtualMachine("test_vm_missing_entry", normalConfig);
 
@@ -1034,7 +1036,7 @@
     @Test
     public void bootFailsWhenBinaryTriesToLinkAgainstPrivateLibs() throws Exception {
         VirtualMachineConfig.Builder builder =
-                newVmConfigBuilder().setPayloadBinaryPath("MicrodroidPrivateLinkingNativeLib.so");
+                newVmConfigBuilder().setPayloadBinaryName("MicrodroidPrivateLinkingNativeLib.so");
         VirtualMachineConfig normalConfig = builder.setDebugLevel(DEBUG_LEVEL_FULL).build();
         VirtualMachine vm = forceCreateNewVirtualMachine("test_vm_private_linking", normalConfig);
 
@@ -1044,9 +1046,7 @@
     @Test
     public void sameInstancesShareTheSameVmObject() throws Exception {
         VirtualMachineConfig config =
-                newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
-                        .build();
+                newVmConfigBuilder().setPayloadBinaryName("MicrodroidTestNativeLib.so").build();
 
         VirtualMachine vm = forceCreateNewVirtualMachine("test_vm", config);
         VirtualMachine vm2 = getVirtualMachineManager().get("test_vm");
@@ -1108,7 +1108,7 @@
         // Arrange
         VirtualMachineConfig.Builder builder =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setDebugLevel(DEBUG_LEVEL_FULL);
         if (encryptedStoreEnabled) builder = builder.setEncryptedStorageKib(4096);
         VirtualMachineConfig config = builder.build();
@@ -1150,7 +1150,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setEncryptedStorageKib(4096)
                         .setDebugLevel(DEBUG_LEVEL_FULL)
@@ -1168,7 +1168,7 @@
 
         final VirtualMachineConfig vmConfig =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .build();
@@ -1187,7 +1187,7 @@
 
         VirtualMachineConfig config =
                 newVmConfigBuilder()
-                        .setPayloadBinaryPath("MicrodroidTestNativeLib.so")
+                        .setPayloadBinaryName("MicrodroidTestNativeLib.so")
                         .setMemoryMib(minMemoryRequired())
                         .setEncryptedStorageKib(4096)
                         .setDebugLevel(DEBUG_LEVEL_FULL)
diff --git a/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachinePayloadConfig.aidl b/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachinePayloadConfig.aidl
index ed3c512..55c2f5d 100644
--- a/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachinePayloadConfig.aidl
+++ b/virtualizationservice/aidl/android/system/virtualizationservice/VirtualMachinePayloadConfig.aidl
@@ -18,8 +18,9 @@
 
 parcelable VirtualMachinePayloadConfig {
     /**
-     * Path to the payload executable code in an APK. The code is in the form of a .so with a
-     * defined entry point; inside the VM this file is loaded and the entry function invoked.
+     * Name of the payload executable file in the lib/<ABI> folder of an APK. The payload is in the
+     * form of a .so with a defined entry point; inside the VM this file is loaded and the entry
+     * function invoked.
      */
-    @utf8InCpp String payloadPath;
+    @utf8InCpp String payloadBinaryName;
 }
diff --git a/virtualizationservice/src/aidl.rs b/virtualizationservice/src/aidl.rs
index 733d9c5..0859a76 100644
--- a/virtualizationservice/src/aidl.rs
+++ b/virtualizationservice/src/aidl.rs
@@ -841,7 +841,7 @@
             load_vm_payload_config_from_file(&apk_file, config_path.as_str())
                 .with_context(|| format!("Couldn't read config from {}", config_path))?
         }
-        Payload::PayloadConfig(payload_config) => create_vm_payload_config(payload_config),
+        Payload::PayloadConfig(payload_config) => create_vm_payload_config(payload_config)?,
     };
 
     // For now, the only supported OS is Microdroid
@@ -887,13 +887,20 @@
     Ok(serde_json::from_reader(config_file)?)
 }
 
-fn create_vm_payload_config(payload_config: &VirtualMachinePayloadConfig) -> VmPayloadConfig {
+fn create_vm_payload_config(
+    payload_config: &VirtualMachinePayloadConfig,
+) -> Result<VmPayloadConfig> {
     // There isn't an actual config file. Construct a synthetic VmPayloadConfig from the explicit
     // parameters we've been given. Microdroid will do something equivalent inside the VM using the
     // payload config that we send it via the metadata file.
-    let task =
-        Task { type_: TaskType::MicrodroidLauncher, command: payload_config.payloadPath.clone() };
-    VmPayloadConfig {
+
+    let payload_binary_name = &payload_config.payloadBinaryName;
+    if payload_binary_name.contains('/') {
+        bail!("Payload binary name must not specify a path: {payload_binary_name}");
+    }
+
+    let task = Task { type_: TaskType::MicrodroidLauncher, command: payload_binary_name.clone() };
+    Ok(VmPayloadConfig {
         os: OsConfig { name: MICRODROID_OS_NAME.to_owned() },
         task: Some(task),
         apexes: vec![],
@@ -901,7 +908,7 @@
         prefer_staged: false,
         export_tombstones: false,
         enable_authfs: false,
-    }
+    })
 }
 
 /// Generates a unique filename to use for a composite disk image.
diff --git a/virtualizationservice/src/payload.rs b/virtualizationservice/src/payload.rs
index eb3e9eb..02e8f8e 100644
--- a/virtualizationservice/src/payload.rs
+++ b/virtualizationservice/src/payload.rs
@@ -194,7 +194,7 @@
 ) -> Result<ParcelFileDescriptor> {
     let payload_metadata = match &app_config.payload {
         Payload::PayloadConfig(payload_config) => PayloadMetadata::config(PayloadConfig {
-            payload_binary_path: payload_config.payloadPath.clone(),
+            payload_binary_name: payload_config.payloadBinaryName.clone(),
             ..Default::default()
         }),
         Payload::ConfigPath(config_path) => {
diff --git a/vm/src/main.rs b/vm/src/main.rs
index 002e505..9fa805e 100644
--- a/vm/src/main.rs
+++ b/vm/src/main.rs
@@ -51,9 +51,10 @@
         #[clap(long)]
         config_path: Option<String>,
 
-        /// Path to VM payload binary within APK (e.g. MicrodroidTestNativeLib.so)
+        /// Name of VM payload binary within APK (e.g. MicrodroidTestNativeLib.so)
         #[clap(long)]
-        payload_path: Option<String>,
+        #[clap(alias = "payload_path")]
+        payload_binary_name: Option<String>,
 
         /// Name of VM
         #[clap(long)]
@@ -258,7 +259,7 @@
             storage,
             storage_size,
             config_path,
-            payload_path,
+            payload_binary_name,
             daemonize,
             console,
             log,
@@ -277,7 +278,7 @@
             storage.as_deref(),
             storage_size,
             config_path,
-            payload_path,
+            payload_binary_name,
             daemonize,
             console.as_deref(),
             log.as_deref(),
diff --git a/vm/src/run.rs b/vm/src/run.rs
index 6096913..b99328a 100644
--- a/vm/src/run.rs
+++ b/vm/src/run.rs
@@ -48,7 +48,7 @@
     storage: Option<&Path>,
     storage_size: Option<u64>,
     config_path: Option<String>,
-    payload_path: Option<String>,
+    payload_binary_name: Option<String>,
     daemonize: bool,
     console_path: Option<&Path>,
     log_path: Option<&Path>,
@@ -117,14 +117,16 @@
     let extra_idsig_fds = extra_idsig_files?.into_iter().map(ParcelFileDescriptor::new).collect();
 
     let payload = if let Some(config_path) = config_path {
-        if payload_path.is_some() {
-            bail!("Only one of --config-path or --payload-path can be defined")
+        if payload_binary_name.is_some() {
+            bail!("Only one of --config-path or --payload-binary-name can be defined")
         }
         Payload::ConfigPath(config_path)
-    } else if let Some(payload_path) = payload_path {
-        Payload::PayloadConfig(VirtualMachinePayloadConfig { payloadPath: payload_path })
+    } else if let Some(payload_binary_name) = payload_binary_name {
+        Payload::PayloadConfig(VirtualMachinePayloadConfig {
+            payloadBinaryName: payload_binary_name,
+        })
     } else {
-        bail!("Either --config-path or --payload-path must be defined")
+        bail!("Either --config-path or --payload-binary-name must be defined")
     };
 
     let payload_config_str = format!("{:?}!{:?}", apk, payload);
@@ -197,7 +199,7 @@
     let instance_img = work_dir.join("instance.img");
     println!("instance.img path: {}", instance_img.display());
 
-    let payload_path = "MicrodroidEmptyPayloadJniLib.so";
+    let payload_binary_name = "MicrodroidEmptyPayloadJniLib.so";
     let extra_sig = [];
     command_run_app(
         name,
@@ -208,7 +210,7 @@
         storage,
         storage_size,
         /* config_path= */ None,
-        Some(payload_path.to_owned()),
+        Some(payload_binary_name.to_owned()),
         daemonize,
         console_path,
         log_path,