Bugtraq mailing list archives
Re: Buffer overflow prevention
From: Tom 7 <twm () andrew cmu edu>
Date: Fri, 15 Aug 2003 14:41:10 -0400 (EDT)
Crispin Cowan <crispin () immunix com> wrote:
Array bounds checking offers greater protection than any of these protections (StackGuard, ProPolice, PointGuard, W^X, PAX/ASLR, etc.) The problem is that the very fastest array bounds protection for C (Bounded Pointers) imposes a 5X slowdown on performance, where as these other techniques impose overheat somewhere between noise and 20%.
This may be true. Doing "safe" pointers in C is difficult because of pointer arithmetic. But I think this is a bit unfair to bounds checking in general--type safe compiled languages like ML achieve array bounds checking (and other checks) at a much smaller penalty (less than 20% for array-oriented code in my experience). These languages also provide protection against other common sources of holes, like integer overflow, double-frees (most are garbage collected) and printf formatting attacks. This protection is automatic and absolute; the only thing left to worry about is bugs in the compiler, system library, and kernel (things that C programmers already need to worry about, anyway). In my opinion these languages are utterly practical for Unix network daemons. Of course, this is a bit more work because you don't just recompile the program, you have to rewrite it from scratch! But there are other benefits to maintaining code in a modern, safe, high-level language. - Tom [ http://www.cs.cmu.edu/~tom7/ ]
Current thread:
- Heterogeneity as a form of obscurity, and its usefulness, (continued)
- Heterogeneity as a form of obscurity, and its usefulness Bob Rogers (Aug 22)
- Re: Heterogeneity as a form of obscurity, and its usefulness Crispin Cowan (Aug 22)
- Re: Heterogeneity as a form of obscurity, and its usefulness Nicholas Weaver (Aug 22)
- Re: [Full-Disclosure] Re: Buffer overflow prevention KF (Aug 15)
- Re: Buffer overflow prevention Patrick Dolan (Aug 14)
- Re: Buffer overflow prevention Theo de Raadt (Aug 18)
- Re: Buffer overflow prevention Peter Busser (Aug 18)
- Re: Buffer overflow prevention noir (Aug 18)
- Re: Buffer overflow prevention Mariusz Woloszyn (Aug 18)
- Re: Buffer overflow prevention Darren Reed (Aug 18)