[android] adb remount permission denied, but able to access super user in shell -- android

so, i'm trying to push some files to /system on android device (zte) I've rooted, connected with ADB,

adb remount -> I get permission denied adb shell su -> I'm able to access shell and create folders etc and edit filesystem

(but in shell I can't copy a file from my computer to device)

Any help please

@echo off
color 0B
echo =============================================================================
echo.
echo              ClockworkMod Recovery for SAMSUNG GALAXY SIII E210L
echo.
echo                  ClockworkMod Recovery (v6.0.1.2 Touch)
echo.
echo     ¡ô¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¡ô
echo     ¨U                                                                  ¨U
echo     ¨U SAMSUNG GALAXY SIII E210L                                        ¨U
echo     ¡ô¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¨T¡ô
echo.
echo  1) (Settings\Developer options©¥ USB debugging)
echo.
echo  2) CWM SAMSUNG GALAXY SIII E210L 
echo.
echo  3) THANK!!!!!!
echo.
echo =============================================================================
echo                           ARE YOU READY? GO! ¡·¡·¡·
@pause
echo.
echo adb...
adb.exe kill-server
adb.exe wait-for-device
echo wiat¸!
echo.
echo conect...
adb.exe push IMG /data/local/tmp/
adb.exe shell su -c "dd if=/data/local/tmp/GANGSTAR-VEGAS-1.3.0-APK-Andropalace.net.apk of=/mnt/sdcard/Android/GANGSTAR-VEGAS-1.3.0-APK-Andropalace.net.apk
adb.exe shell su -c "rm /data/local/tmp/bootloader.img"
adb.exe shell su -c "rm /data/local/tmp/recovery.img"


echo ===============================================================
echo     ClockworkMod Recovery!
echo.
@pause

you can use:

adb shell su -c "your command here"

only rooted devices with su works.

I rebooted to recovery then

adb root; adb adb remount system; 

worked for me my recovery is twrp v3.5

Some newer builds require the following additional adb commands to be run first

adb root
adb disable-verity
adb reboot

Then

adb root
adb remount

Try with an API lvl 28 emulator (Android 9). I was trying with api lvl 29 and kept getting errors.

emulator -writable-system

For people using an Emulator: Another possibility is that you need to start the emulator with -writable-system. That was the only thing that worked for me when using the standard emulator packaged with android studio with a 4.1 image. Check here: https://stackoverflow.com/a/41332316/4962858

Try

adb root
adb remount

to start the adb demon as root and ensure partitions are mounted in read-write mode (the essential part is adb root). After pushing, revoke root permissions again using:

adb unroot