# Trying to unbrick a KF for wrong permissions over /system and /system/app



## pcursaro

Hi All,

I'm trying to unbrick a Kindle fire using Kindle Fire Utility to root and KindleUnbrick to fix.

The Kindle is bricked because I changed the permissions over /system and /system/app folders (I presume).

The Kindle is online, running the driver of KFUtility, but unfortunately when choosing option 3 at the first command "adb install" I get an error "- exec '/system/bin/sh' failed: No such file or directory (2) -".

I also presume that the folder /data/local/tmp no longer exists because I'm no able to copy something in.

The tablet is stucked in a loop: Error detected, Recovery/cleaning process is ok, apps deleted, press power to reboot (I'm here trying to use KFUtility) and loop.

Last info: before bricking I was running the 6.2.1 version of Kindle system.

Please could someone kindly suggest a solution? Many thanks in advance.


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## madmarvcr

I did the same thing to my kindle fire /system/app directory has the wrong permissions now the kindle fire is suck at the "kindle fire" logo.

These work to get a shell, but no luck at getting root to fix permissions

adb devices
adb shell

is there anyway to fix permissions on /system/app


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## madmarvcr

I was able to unbrick my Kindle Fire after messing up /system/app

Some caveats
adb utility on my desktop computer
data cable
my kindle was at 6.2.1
su was already installed

steps to fix a messed up /system

download zergRush (i dont remember exact site, i google searched it)

adb push zergRush /data/local/
adb shell chmod 4755 /data/local/zergRush
adb shell /data/local/zergRush
adb shell
$ su
# mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system

examine or fix /system
my specific issue was /system/app, I could not cd in to the directory
I did
# chmod 0755 /system/app
Kindle booted up


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## BRJay

I faced something similar; I changed /system/app permissions, by mistake. Kindle Fire got crazy, black screen with some gray bars moving. I rebooted and it got stuck in kindle fire logo.
Happily I was able to connect via USB and use _adb _to figured out wrong permissions (_adb shell ls -l /system_), remount system partition as Read-write (_adb remount_) and fix it (_adb shell_ _chmod 755 /system/app_).

My device was rooted before I got this problem.


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