On Sat, Jun 5, 2021 at 2:17 PM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > On Sat, Jun 5, 2021 at 11:11 AM Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote: > > > > You have fallen into a common fallacy. The fact that the "code runs" > > does not assure that the "system works right". In the security world > > we face this all the time, often with performance expectations. In this > > case the BPF design has failed [..] > > I think it's the lockdown patches that have failed. They did the wrong > thing, they didn't work, > > The report in question is for a regression. > > THERE ARE NO VALID ARGUMENTS FOR REGRESSIONS. To think I was worried we might end this thread without a bit of CAPS LOCK, whew! :) I don't think anyone in this discussion, even Casey's last comment, was denying that there was a problem. The discussion and the disagreements were about what a "proper" fix would be, and how one might implement that fix; of course there were different ideas of "proper" and implementations vary even when people agree, so things were a bit of a mess. If you want to get upset and shouty, I think there are a few things spread across the subsystems involved that would be worthy targets, but to say that Casey, myself, or anyone else who plays under security/ denied the problem in this thread is not fair, or correct, in my opinion. > Honestly, security people need to understand that "not working" is not > a success case of security. It's a failure case. I can't pretend to know what all of the "security people" are thinking, but I can say with a good degree of certainty that my goal is not to crash, panic, kill, or otherwise disable a user's system. When it comes to things like the LSM hooks, my goal is to try and make sure we have the right hooks in the right places so that admins and users have the tools they need to control access to their data and systems in the way that they choose. Sometimes this puts us at odds with other subsystems in the kernel, we saw that in this thread, but that's to be expected anytime you have competing priorities. The important part is that eventually we figure out some way to move forward, and the fact that we are still all making progress and putting out new kernel releases is proof that we are finding a way. That's what matters to me, and if I was forced to guess, I would imagine that matters quite a lot to most of us here. -- paul moore www.paul-moore.com
