Cap'n'Proto remote vuln: pointer overflow check optimized away by compiler
For people claiming that this is a compiler bug, it really is not.<p>I am no expert, but what I understood is that the C standard defines some situations (such as an overflow error) which result in "undefined behaviour". In this situation, the compiler is free to do whatever he wants. This is in fact what happens here.<p>This is clearly annoying to programmers. In this case, it is even hard to avoid undefined behaviour even if the source of undefined behaviour (a pointer overflow) is known.<p>Why is this done? This way the compiler can do some aggresive optimizations which are only valid if there is no undefined behaviour (e.g. no overflow, null pointer acces...).<p>There are various good articles about this.<p>To make the situation more complex for programmers, it is possible to write programs which exhibit undefined behaviour but work fine in practice. Until the compiler tries to do a specific optimization.<p>This is basically why you shouldn't use C. Long-time C programmers know a list of operations which are undefined behaviour, and are usually able to point out a few of these in a program written by newbie (ironically, these programs may run and pass tests just fine).