Hacker News Reader

I wonder how it handles a bogus printf format string.

The same way the underlying printf implementation does? This isn't wrapping printf(3), just the underlying write(2).

Are you trying to ask if it catches, e.g., format string vulnerabilities? I think the answer to that is: Native Client's aim is to be a safe x86 VM, so — hopefully. But to me personally, it seems unlikely that they've thought of everything.

The important part of the design - the bit that makes it achievable - is that it's not a general x86 VM. It only accepts a limited subset of valid x86 object code, a subset chosen to make validation a tractable problem. This requires a modified compiler be used.

The unlikelihood that the original design was perfect is probably why they had the "Native Client Security Contest" a few years ago - and indeed independent researchers found several flaws. Personally, I'm a lot happier with it now that they've fixed everything that Mark Dowd could find wrong with it ;)

Reply on news.ycombinator.com