De Raadt + FBSD + OpenSSH + hole?

[Jamie Landeg-Jones]

> I wonder how many security holes, both those known and as yet unrevealed 
> or unknown, would not be of any exploit value if in all security related 
> libraries and applications the routine to free allocated memory 
> allocation closest to the user app/library  set the newly free memory to 
> a known pattern or something from /dev/random before returning.  And, 
> similarly, a compiler option causing function returns using more than a 
> few dozen bytes of stack space to erase the newly freed stack region 

I'm probably being really dense here, and realise I can't delete this
post once sent! But....

Once memory has been freed, I thought any attempt by a user process to
access it would cause a SIGSEV.

I thought the issue was with programs that inadvertantly expose (either
to read or write) other parts of their active memory.

Of course, if a process rolls it's own in-process implementation
of malloc/free, then this point is moot, but once you free memory back
to the system, isn't in no longer accessable anyway?

Cheers,
       Jamie