Password theft from memory?

[RW]

On Fri, 29 Apr 2011 12:00:00 -0400
Bob Hall <rjhjr0 at gmail.com> wrote:

> On Fri, Apr 29, 2011 at 01:54:06AM +0100, RW wrote:

> > but they aren't the same - that's what the quotes were about. 
> 
> Looking back, I don't see anything in your quotes that raises the
> issue of anonymous objects being used differently.


If you don't already know that memory is zeroed by default it
would be obtuse to infer that arbitrarily sized anonymous mappings are
zero-filled, just because a few bytes of padding are zero-filled.
Consequently your quote had no relevance to whether memory obtained by
malloc is zero-filled.

However, by taking that sentence out of context it was made unclear what
"extensions" referred to. A casual reader could have assumed that it
was possible to make zero-filled extensions to the object through mmap.
If that were true then your position, that the two cases are similar,
would be be quite reasonable. I assumed that you had misread the man
page.