Parasitic manager crash-loops on GrapheneOS with ptrace-based Zygisk — `DENY_PROCESS_PTRACE` left armed on the host

[david568303]

Steps to reproduce/复现步骤

Install Vector normally, and try to open the Vector notification

Expected behaviour/预期行为

Vector actually opening

Actual behaviour/实际行为

Vector never opens

Xposed Module List/Xposed 模块列表

NeoZygisk

Root implementation/Root 方案

Apatch on 6.6 kernel

System Module List/系统模块列表

NeoZygisk
Vector

Vector version/Vector 版本

3112, but it happends on stable too.

Android version/Android 版本

17

Version requirement/版本要求

• I am using the latest debug build from GitHub Actions./我正在使用 GitHub Actions 中最新的调试版本。

Logs/日志

F DEBUG : Abort message: 'JNI FatalError called: (org.matrix.vector.manager)
frameworks/base/core/jni/com_android_internal_os_Zygote.cpp:2111:
selinux_android_setcontext(2000, 0,
"platform:privapp:targetSdkVersion=36:partition=system:complete",
"org.matrix.vector.manager", grapheneos_flags: "100") failed'
I Zygote : Process exited due to signal 6 (Aborted)
...ExecSpawning.replayCommands ... ZygoteServer.runSelectLoop ... ZygoteInit.main

[david568303]

Summary

On GrapheneOS, opening the parasitic manager (module only, no standalone manager.apk installed) crash-loops the zygote and the manager never appears. This happens even with the existing GrapheneDclHooker in place. The cause is one GrapheneOS grapheneos_flags bit — DENY_PROCESS_PTRACE — that is not cleared for the manager host, and it only bites when the Zygisk implementation injects over ptrace (NeoZygisk / ReZygisk). Clearing it for the host (same mechanism GrapheneDclHooker already uses for the DCL switches) fixes it; verified on hardware.

Likely the same underlying problem as the Android-17 reports in #759 and the selinux_android_setcontext crash in #904.

Environment

• Device: Pixel 10 Pro XL (mustang), GrapheneOS, Android 17, build 2026100201
• Root: APatch (KernelPatch) + NeoZygisk v2.4 (289) — ptrace-based Zygisk
• Vector: v2.2 canary 3112 (so GrapheneDclHooker / PR Let the parasitic manager load its DEX on GrapheneOS #805 is present)
• No standalone manager installed (pure module / parasitic)

Symptom

Tapping the status notification (or the launcher shortcut) aborts the host spawn, repeatedly:

F DEBUG : Abort message: 'JNI FatalError called: (org.matrix.vector.manager)
  frameworks/base/core/jni/com_android_internal_os_Zygote.cpp:2111:
  selinux_android_setcontext(2000, 0,
    "platform:privapp:targetSdkVersion=36:partition=system:complete",
    "org.matrix.vector.manager", grapheneos_flags: "100") failed'
I Zygote : Process <pid> exited due to signal 6 (Aborted)
...ExecSpawning.replayCommands ... ZygoteServer.runSelectLoop ... ZygoteInit.main

Root cause

grapheneos_flags is SELinuxFlags, printed in hex. 0x100 == 1 << 8 == SELinuxFlags.DENY_PROCESS_PTRACE.

SELinuxFlags.get() starts from ALL_RESTRICTIONS and only clears DENY_PROCESS_PTRACE when AswDenyNativeDebug returns false. But AswDenyNativeDebug.getImmutableValue() returns true immutably for every system app — and the parasitic host, com.android.shell, is a system app. So the flag is always armed for the host.

GrapheneDclHooker already forces the three AswRestrict*DynCodeLoading switches off for the host, which strips SELinuxFlags bits 0–7 — that is exactly why the only surviving flag in the abort message is 0x100. The manager host is injected over ptrace (NeoZygisk/ReZygisk), and with DENY_PROCESS_PTRACE set the host process's SELinux context transition in selinux_android_setcontext2() fails (-1), so the spawn aborts and the manager crash-loops. GrapheneDclHooker covered the DCL channel but not this one.

Fix

Add AswDenyNativeDebug to the set of AppSwitches GrapheneDclHooker already forces to false for the manager host — identical getImmutableValue override, identical host-only guard. That clears DENY_PROCESS_PTRACE for com.android.shell alone, so the parasitic manager specializes and the notification opens it, module-only, with no standalone APK. Every other app keeps GrapheneOS's normal ptrace denial.

Patch (branch): https://github.com/david568303/Vector/tree/fix/graphene-parasitic-manager

Verification

Built the module from the branch and flashed it over the existing zygisk_vector (Pixel 10 Pro XL, GrapheneOS Android 17, NeoZygisk v2.4), with no standalone manager installed. Before: notification crash-loops the zygote with the abort above. After: the parasitic manager opens from the notification and the framework is Active.

Scope / security note

The exemption is host-only (com.android.shell) and clears only DENY_PROCESS_PTRACE. The Zygisk injector already ptraces that host process to inject — the flag was only making the SELinux transition fail — so this does not add exposure beyond what injection already requires, and it mirrors the tradeoff GrapheneDclHooker already makes for the DCL flags. A reviewer may prefer to scope it to the manager spawn specifically rather than all of com.android.shell.

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Generated by Claude Code

[JingMatrix]

Did you try #123 ?

[david568303]

Did you try #123 ?

Wow, thanks for your quick reply.

Well, i did try it, and i only had success if i installed the manager.apk as su.

I also had to disable Secure App Launching for the installed manager to work, same goes for if using the module only.