[cygwin] DD bug fails to wipe last 48 sectors of a disk

[Eliot Moss]

On 6/20/2020 1:31 PM, Hashim Aziz via Cygwin wrote:
> To reproduce simply run the following command on a drive (obviously, this will irreversibly wipe all data):
> 
> dd if=/dev/zero of=/dev/sdX bs=4M status=progress
> 
> Both drives were attached via internal SATA (by way of a PCIE to SATA Host Bus Adapter).
> 
> Cygwin was running in an elevated window as dd cannot run in Cygwin without administrator access, at least not on Windows 10 and not when dealing with raw disks. I was running Avast the first time I discovered this, and am currently running Windows Defender, so doubt that the AV is the cause of this.
> 
> The hard drives are a Western Digital WD10PURX-64E5EY0 (Serial: WD-WCC4J6HX189U) and a Kingston SV200S3128G (Serial: 12BA315PKAWK).
> 
> I just ran DD for Windows 0.6beta3 with variations of the following command:
> 
> dd.exe if=/dev/zero of=\\.\PHYSICALDRIVEX --progress bs=4M
> 
> ...and can confirm that the bug also manifests here, but in a slightly different way - irrespective of the disk or block size, it fails to wipe the last 176 sectors of the drive.

I was going to ask: even with block size 512 bytes?  But I guess you checked that ...

Regards - Eliot