On 04/15/2014 09:56 AM, Matthew Black wrote:
From: Doug Barton [mailto:dougb@dougbarton.us]
When you say "clear the disk allocated to programs" what do you mean exactly?
Seriously? When files are deleted, their sectors are simply released to the free space pool without erasing their contents. Allocation of disk sectors without clearing them gives users/programs access to file contents previously stored by other users/programs.
As to why this is a problem, well, as they write in some math textbooks, the answer is trivial and left as an exercise to the reader. Well, usually trivial.
matthew black california state university, long beach
Bruce Schneier gave a plug for bleachbit - it does a reasonable job of trying to clean things up for you.
-----Original Message----- From: Doug Barton [mailto:dougb@dougbarton.us] Sent: Monday, April 14, 2014 7:48 PM To: nanog@nanog.org Subject: Re: [[Infowarrior] - NSA Said to Have Used Heartbleed Bug for Years]
On 04/14/2014 05:50 PM, John Levine wrote:
In article <534C68F4.305@cox.net> you write:
On 4/14/2014 9:38 AM, Matthew Black wrote:
Shouldn't a decent OS scrub RAM and disk sectors before allocating them to processes, unless that process enters processor privileged mode and sets a call flag? I recall digging through disk sectors on RSTS/E to look for passwords and other interesting stuff over 30 years ago.
I have been out of the loop for quite a while but my strongly held belief is that such scrubbing would be an enormous (and intolerable) overhead ...
It must be quite a while. Unix systems have routinely cleared the RAM and disk allocated to programs since the earliest days.
When you say "clear the disk allocated to programs" what do you mean exactly?
-- Glen Wiley KK4SFV