Home > Computer forensics > Mounting a JFFS2 dd image in Linux

Mounting a JFFS2 dd image in Linux

So there I was, holding a dd image of a JFFS2 filesystem dumped from a drone. Great, good to go! Let’s start our analysis! Not so fast, mounting one of these things is non-trivial. After much trial and error, and some Google-fu, I got the following to work in the SIFT3 forensics VM (Ubuntu).

First, test to see if the image is recognized:

khorog:dot2 kovar$ file root.dd
root.dd: data

Not a recognized filesystem and the most likely issue is big vs little endian. Let’s fix that:

apt-get install mtd-utils
jffs2dump -b -c -r -e dest_file.little src_file.big

Note: The ‘-r’ was critical and none of the Google hits I found on this topic included it. This option “recalc name and data crc on endian conversion”.

Now, check the file again:

khorog:dot2 kovar$ file root-swap.dd
root-swap.dd: Linux jffs2 filesystem data little endian

Then install a lot of kernel modules. (Some of these failed in Ubuntu 14 but the mount worked anyhow.)

modprobe mtdcore
modprobe jffs2
modprobe mtdram
modprobe mtdchar
modprobe mtdblock

Now, mount the image:

dd if=root-swap.dd of=/dev/mtdblock0
mount -t jffs2 /dev/mtdblock0 /mnt/jffs2

Et viola.

Categories: Computer forensics
  1. May 10, 2016 at 8:52 pm

    Distributor ID: Ubuntu
    Description: Ubuntu 16.04 LTS
    Release: 16.04
    Codename: xenial

    $file root_cfe_auto.jffs2
    root_cfe_auto.jffs2: UBI image, version 1

    $modprobe nandsim first_id_byte=0x2c second_id_byte=0xda third_id_byte=0x90 fourth_id_byte=0x95
    $flash_erase /dev/mtd0 0 0
    $ubiformat /dev/mtd0 -O 2048 -f Documents/vuplus/solo/root_cfe_auto.jffs2
    $modprobe ubi
    $ubiattach /dev/ubi_ctrl -m 0 -O 2048
    $mkdir /media/jffs2
    $mount -t ubifs ubi0:rootfs /media/jffs2

  2. May 24, 2016 at 8:02 am

    Thanks ! Strangely some of the commands indeed dont work but the mounting itself worked on Ubuntu. Just needed to add sudo, but that speaks for itself 😉 Thanks !

  1. October 30, 2015 at 9:03 am

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