On Mon, 30 Apr 2018 16:31:52 +0000 Linus Torvalds <torva...@linux-foundation.org> wrote:
> On Mon, Apr 30, 2018 at 9:11 AM Kees Cook <keesc...@chromium.org> wrote: > > > I (or other folks?) had proposed this before, but, AIUI, Linus remains > > opposed. > > Yeah, I hate this, because it will make people paper over their problems by > just booting with that option. > > I think it should just be fixed. > > Is there really any reason why trace buffers have to be dumped so early > that the entropy hasn't even taken yet? In this case, an RCU stall was triggering and a "dump on oops" would dump the trace buffers, (before entropy was established). > > And if we really want a command line option, can we make that still hash > the pointer, just force the entropy early. That way kernel developers that > test that command line option are still testing the *hashing*, they just > are missing the good entropy. > That may work too. Even with bad entropy, pointers at start up are hard to come by, and I can't see a hacker being able to use them as it only happens once during boot. -- Steve
