Re: Buffer overflow prevention

[Glynn Clements <glynn.clements@virgin.net>]

Theo de Raadt wrote:

> One of these days someone is going to use the magic of a system call
> interposition mechanism such systrace; and for their application
> accidentally create an operating system behaviour that is un-POSIX,
> and some application is going to misbehave as a result of that change
> and inadvertantly this will result in the CREATION of a hole.

For a concrete example regarding POSIX 1e capabilities (which
are essentially a "system call interposition mechanism"):

	http://ciac.llnl.gov/ciac/bulletins/k-064.shtml

Summary: If a root process doesn't have CAP_SETUID, attempts to give
up root privilege fail, resulting in the process continuing to run as
root.

-- 
Glynn Clements <glynn.clements@virgin.net>