Am Dienstag, 10. September 2013, 14:25:24 schrieb Theodore Ts'o: Hi Theodore,
> >Also note that the clocksource is not necessarily be the best choice; >it may not be the most fine grained sampling that we have available >(that is certainly be true for MIPS). So doing something hacky >doesn't absolve us from the need to example every single platform that >as a no-op get_cycles() function. (Well, at least those platforms >that we think really are going to be running security sensitive >systems ---- does anyone think we really have production systems >running m68k? Maybe, but....) That is why I arranged the clocksource call after get_cycles does not return anything, so it would only be used if get_cycles does not have anything. But then, your experience with clocksource really has a point. > >If we believed that /dev/random was actually returning numbers which >are exploitable, because of this, I might agree with the "we must do >SOMETHING" attitude. But I don't believe this to be the case. Also >note that we're talking about embedded platforms, where upgrade cycles >are measured in years --- if you're lucky. There are probably home >routers still stuck on 2.6, at which point they will be far more >succeptible to the problems described at http://factorable.net. The core problem I guess on this matter is again the strange use of /dev/random in embedded devices -- no seeding, no spinning disks, no heads, no nothing. Here my CPU jitter RNG would help, but there seems to be no interest in even discussing it... PS: I have my CPU jitter RNG running running as an entropy feeder daemon nicely on my router box, though, which happens to be a MIPS box... > >So I don't think we need to rush. I'd much rather make sure we get >this fixed right. > > - Ted Ciao Stephan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
