[Bug]: (termux-api) termux-clipboard-set not working on Android 14

[AntonPieper]

Problem description

On Android 14 Beta, trying to run

termux-clipboard-set "test"

will result in the cursor returning to the next line (hanging forever), not copying "Test" and the program not exiting (only by pressing Ctrl + C).

Screenshot:

What steps will reproduce the bug?

Install Termux:API from F-Droid, then install termux-clipboard-set by running

pkg install termux-api

lastly try to set the clipboard via

termux-clipboard-set "test"

What is the expected behavior?

It should not hang forever. It should set the clipboard and return.

System information

termux-info:

Termux Variables:
TERMUX_API_VERSION=0.50.1
TERMUX_APK_RELEASE=F_DROID
TERMUX_APP_PACKAGE_MANAGER=apt
TERMUX_APP_PID=19024
TERMUX_IS_DEBUGGABLE_BUILD=0
TERMUX_MAIN_PACKAGE_FORMAT=debian
TERMUX_VERSION=0.118.0
Packages CPU architecture:
aarch64
Subscribed repositories:
# sources.list
deb https://packages-cf.termux.dev/apt/termux-main stable main
Updatable packages:
clang/stable 16.0.2 aarch64 [upgradable from: 16.0.1-1]
command-not-found/stable 2.1.0-20 aarch64 [upgradable from: 2.1.0-19]
coreutils/stable 9.3 aarch64 [upgradable from: 9.2-4]
glib/stable 2.76.2 aarch64 [upgradable from: 2.76.1]
libcompiler-rt/stable 16.0.2 aarch64 [upgradable from: 16.0.1-1]
libllvm/stable 16.0.2 aarch64 [upgradable from: 16.0.1-1]
libmpfr/stable 4.2.0-p4-0 aarch64 [upgradable from: 4.2.0]
lld/stable 16.0.2 aarch64 [upgradable from: 16.0.1-1]
llvm/stable 16.0.2 aarch64 [upgradable from: 16.0.1-1]
python-pip/stable 23.1.1 all [upgradable from: 23.1]
rust-analyzer/stable 20230320 aarch64 [upgradable from: 20230220]
rust/stable 1.69.0 aarch64 [upgradable from: 1.68.2]
termux-tools/stable 1.38.1 all [upgradable from: 1.38.0]
termux-tools version:
1.36.1
Android version:
13
Kernel build information:
Linux localhost 5.10.149-android13-4-693040-g6422af733678-ab9739629 #1 SMP PREEMPT Fri Mar 10 01:44:38 UTC 2023 aarch64 Android
Device manufacturer:
Google
Device model:
Pixel 7 Pro
LD Variables:
LD_LIBRARY_PATH=
LD_PRELOAD=/data/data/com.termux/files/usr/lib/libtermux-exec.so

[aicynide]

See termux-info, its a13

[sylirre]

@aicynide Sometimes the beta version of Android OS is displayed as previous one. The system SDK level is more accurate then version number returned by getprop.

Edit: perhaps even SDK level not changed. The only difference I see is the release name. For Android 14 this is "UpsideDownCake", aka Android U.

ADB getprop values on Android 14 (dev) GSI:

[ro.build.version.preview_sdk]: [1]
[ro.build.version.preview_sdk_fingerprint]: [649baee05dadd66233ce9eaf03b06712]
[ro.build.version.release]: [13]
[ro.build.version.release_or_codename]: [UpsideDownCake]
[ro.build.version.release_or_preview_display]: [UpsideDownCake]
[ro.build.version.sdk]: [33]
[ro.build.version.security_patch]: [2023-04-05]

Screenshot from GSI installed on my device (Pixel 5) using dynamic system updates (side-by-side installation with stable OS version):

Will try to get some information what is going on with Termux:API...

[sylirre]

This is new W^X enforcement:

04-26 16:26:02.221  8073  8073 E app_process: Attempt to load writable dex file: /data/data/com.termux/files/usr/libexec/termux-am/am.apk
04-26 16:26:02.221  8073  8073 W System  : No Compatibility callbacks set! Querying change 218865702
04-26 16:26:02.221  8073  8073 W app_process: Ljava/lang/ClassLoader$SystemClassLoader; failed initialization: java.lang.SecurityException: Writable dex file '/data/data/com.termux/files/usr/libexec/termux-am/am.apk' is not allowed.
04-26 16:26:02.221  8073  8073 W app_process:   at java.lang.Object dalvik.system.DexFile.openDexFileNative(java.lang.String, java.lang.String, int, java.lang.ClassLoader, dalvik.system.DexPathList$Element[]) (DexFile.java:-2)
04-26 16:26:02.221  8073  8073 W app_process:   at java.lang.Object dalvik.system.DexFile.openDexFile(java.lang.String, java.lang.String, int, java.lang.ClassLoader, dalvik.system.DexPathList$Element[]) (DexFile.java:406)
04-26 16:26:02.221  8073  8073 W app_process:   at void dalvik.system.DexFile.<init>(java.lang.String, java.lang.ClassLoader, dalvik.system.DexPathList$Element[]) (DexFile.java:128)
04-26 16:26:02.221  8073  8073 W app_process:   at void dalvik.system.DexFile.<init>(java.io.File, java.lang.ClassLoader, dalvik.system.DexPathList$Element[]) (DexFile.java:101)
04-26 16:26:02.221  8073  8073 W app_process:   at dalvik.system.DexFile dalvik.system.DexPathList.loadDexFile(java.io.File, java.io.File, java.lang.ClassLoader, dalvik.system.DexPathList$Element[]) (DexPathList.java:438)
04-26 16:26:02.221  8073  8073 W app_process:   at dalvik.system.DexPathList$Element[] dalvik.system.DexPathList.makeDexElements(java.util.List, java.io.File, java.util.List, java.lang.ClassLoader, boolean) (DexPathList.java:397)
04-26 16:26:02.221  8073  8073 W app_process:   at void dalvik.system.DexPathList.<init>(java.lang.ClassLoader, java.lang.String, java.lang.String, java.io.File, boolean) (DexPathList.java:166)
04-26 16:26:02.221  8073  8073 W app_process:   at void dalvik.system.BaseDexClassLoader.<init>(java.lang.String, java.lang.String, java.lang.ClassLoader, java.lang.ClassLoader[], java.lang.ClassLoader[], boolean) (BaseDexClassLoader.java:160)
04-26 16:26:02.221  8073  8073 W app_process:   at void dalvik.system.BaseDexClassLoader.<init>(java.lang.String, java.io.File, java.lang.String, java.lang.ClassLoader) (BaseDexClassLoader.java:105)
04-26 16:26:02.221  8073  8073 W app_process:   at void dalvik.system.PathClassLoader.<init>(java.lang.String, java.lang.String, java.lang.ClassLoader) (PathClassLoader.java:71)
04-26 16:26:02.221  8073  8073 W app_process:   at java.lang.ClassLoader java.lang.ClassLoader.createSystemClassLoader() (ClassLoader.java:224)
04-26 16:26:02.221  8073  8073 W app_process:   at java.lang.ClassLoader java.lang.ClassLoader.-$$Nest$smcreateSystemClassLoader() (ClassLoader.java:-1)
04-26 16:26:02.221  8073  8073 W app_process:   at void java.lang.ClassLoader$SystemClassLoader.<clinit>() (ClassLoader.java:183)
04-26 16:26:02.221  8073  8073 W app_process:   at java.lang.ClassLoader java.lang.ClassLoader.getSystemClassLoader() (ClassLoader.java:1098)
04-26 16:26:02.221  8073  8073 F app_process: runtime.cc:903] Check failed: system_class_loader != nullptr 
04-26 16:26:02.277  1026  1032 W statsd  : StatsPullerManager: Unknown tagId 10108

DEX files with write permission are not allowed to be executed, though the fix is trivial. Just run:

chmod 400 $PREFIX/libexec/termux-am/am.apk

This is basically a duplicate of #16255.

termux-clipboard-set and termux-clipboard-get work perfectly under Android 14 after chmod 400 on the termux-am files.

---

Other issues related to W^X hardening:

• No more exec from data folder on targetAPI >= Android Q termux-app#1072
• Revisit the Android W^X problem termux-app#2155