[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Write protect access on USB port

Andrei POPESCU <andreimpopescu <at> gmail.com> writes:

> On Lu, 26 nov 12, 22:33:51, Amit wrote:
> > 
> > Yes, I basically want to avoid even the root user (or process with root
> > privileges) to able to access this. So the kernel has to be replaced in
> > order to disable the "write protect" on that USB port.
> > 
> > It is more of a guarantee that there can be no accidental write on that
> > device plugged in to that port.
> There is no guarantee besides removing the device from the port[1]. Even 
> if you were to remove write support from the usb-storage module (or 
> whatever part of the kernel is responsible for that), one can still 
> accidentally boot another kernel.
> [1] and if you're worried about data corruption this is still not enough
> What exactly are you trying to achieve? Maybe we can suggest better 
> ways.
> Kind regards,
> Andrei

Thanks for the response.

This is more of a personal use case. That is, I end up analyzing hard
drives using the regular Linux tools (hdparm, datadump, etc.) and my own
custom C programs that simply open /dev/sd[x] and read and analyze data.

Now, for example, there have been cases where I accidentaly (as root),
do a dd and overwrite a portion of the drive I was analyzing/reading from.

So by modifying the kernel to disable writes to this port, I can give
myself a personal guarantee that no matter what I or the programs I have
written do, no writes will get through.

I am aware I can image these drives by using dd and then analyzing the
dd image. However, I would like to avoid this if possible. The main
reason is because my current system has very limited hard drive space
and is quite slow (500MHz G4 PPC).

I hope this use case makes sense.


Reply to: