LD_LIBRARY_PATH can no longer be set on Android 12
WandersonKalil opened this issue · comments
@topjohnwu @OSMOSIS I'm the author of SuperPower - Root Access Manager!
After trying to run magiskpolicy from SuperPower's su binary, I get the following error/bug: CANNOT LINK EXECUTABLE "/system/bin/supolicy" : library "libc.so" needed or dlopened by "/system/bin/magiskpolicy" is not accessible for the namespace "default"
My guess is that calling setenv("LD_LIBRARY_PATH", "/system/lib"); no longer works. Android 12 doesn't allow setting LD_LIBRARY_PATH from c code.
@topjohnwu SuperPower 's su binary needs to patch sepolicy in order to work properly: also, there is a policy that is not patched by magiskpolicy that will prevent the su's daemon socket connection: supolicy --live "allow unstrusted_app_all magisk unix_stream_socket connectto". Could you add that policy patch into magiskpolicy?
@topjohnwu would you like to implement SuperPower's full command logging into magiskSU in order to be more complete and compatible with SuperPower?
This issue is fixed by commit e0329ce
since we cannot call setenv("LD_LIBRARY_PATH", "/system/lib", 1) from su binary on Android 12, the solution is to inherit the environment of the caller process for a new process image and call execve().
Update: It's impossible to call /system/bin/supolicy from the daemon through execve(), even stealing zygote's environment. @topjohnwu could you add the sepolicy patch fix for su binary into magiskpolicy?
Update: Android 12 removes LD_LIBRARY_PATH from the execve() syscall!
As the daemon cannot set LD_LIBRARY_PATH, the only solution is to call supolicy from SuperPower's su's shell, whose environment is inherited from the caller process (SuperPower in this case). Consider this issue as Fixed!
Since Android 12 is arm64-v8a bit/abi by default, by setting the LD_LIBRARY_PATH to /system/lib, the kernel will use /system/lib/libc.so instead of /system/lib64/libc.so, causing the following error/bug in the daemon:
02-09 14:10:10.862 20350 20350 F linker : CANNOT LINK EXECUTABLE "sh": library "libc.so" needed or dlopened by "/system/bin/sh" is not accessible for the namespace "(default)"
02-09 14:25:21.068 24232 24232 E linker : library "libc.so" ("/apex/com.android.runtime/lib/bionic/libc.so") needed or dlopened by "/system/bin/sh" is not accessible for the namespace: [name="(default)", ld_library_paths="/vendor/lib:/vendor/lib64:/system/lib:/system/lib64", default_library_paths="/system/lib64:/system/system_ext/lib64", permitted_paths="/system/lib64/drm:/system/lib64/extractors:/system/lib64/hw:/system/system_ext/lib64:/system/framework:/system/app:/system/priv-app:/system/system_ext/framework:/system/system_ext/app:/system/system_ext/priv-app:/vendor/framework:/vendor/app:/vendor/priv-app:/system/vendor/framework:/system/vendor/app:/system/vendor/priv-app:/odm/framework:/odm/app:/odm/priv-app:/oem/app:/product/framework:/product/app:/product/priv-app:/data:/mnt/expand:/apex/com.android.runtime/lib64/bionic:/system/lib64/bootstrap"]
/system/lib64 needs to be the first path to be searched/dlopened by /system/bin/sh instead of /system/lib in order to fix the above bug in su daemon on Android 12 onwards.