#StackBounty: #data-recovery #squashfs #forensics Fix/Repair Can't find a SQUASHFS superblock

Bounty: 100

I have an old filesystem backup that I made and compressed into a squashfs. It was stored on an ext4 filesystem, and I suspect it suffered from some bitrot. I don’t have a backup of the file. Is there any way I might be able to rescue this squashfs archive?

$ unsquashfs olddrive.sfs
Can't find a SQUASHFS superblock on olddrive.sfs

Edit: Adding Info

$ file olddrive.sfs
olddrive.sfs: data
$ sudo mount -t squashfs -o ro olddrive.sfs /tmp/sq
mount: /tmp/sq: wrong fs type, bad option, bad superblock on /dev/loop10, missing codepage or helper program, or other error.

Edit: Interestingly, running hexdump on the file shows that it starts entirely with zero’s. Perhaps reading the file from disk had some bad sectors, and they were replaced with zero’s?

0000000 0000 0000 0000 0000 0000 0000 0000 0000
0000060 8008 0000 0010 0008 0000 37fd 587a 005a                   
0000070 0100 2269 36de c003 ffa5 8003 4080 0121                   
0000080 0010 e48c b888 59ef efe8 5dfe 7500 0d80                   
0000090 8c81 25e2 b847 a0cc 766a b649 c919 3768

Get this bounty!!!

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