Security issue in Terminal

[Guido Berhoerster]

* Kevin Chadwick <ma1l1ists at yahoo.co.uk> [2012-03-09 17:04]:
> On Fri, 9 Mar 2012 12:46:21 +0100
> Guido Berhoerster wrote:
> 
> > Well, you can keep repeating that but it still doesn't make any sense.
> 
> So, your saying you think it's impossible to create a 10MB file without
> actually writing 10MB of data?

That depends on both the operating system and the file system,
it may transparently create a sparse file or not initialize
blocks preallocated via posix_fallocate(). However, you have no
control over that from userspace and filesystems keep track of
what blocks have actually been written and will prevent reading
uninitialized uninitialized block transparently.

> Maybe the code I saw was bogus, I never
> tested it. I don't see why anyone would falsely purport to being able
> to do that though.

Yes, that's bogus.
-- 
Guido Berhoerster