Messages in this thread | | | From | Kees Cook <> | Date | Tue, 3 Apr 2018 13:07:58 -0700 | Subject | Re: [RFC][PATCH] tracing, printk: Force no hashing when trace_printk() is used |
| |
On Tue, Apr 3, 2018 at 12:41 PM, Steven Rostedt <rostedt@goodmis.org> wrote: > Both trace_debug is set and kptr_restrict is set to zero in the same > code that produces the above banner. This will allow trace_printk() to > not be affected by security code, as trace_printk() should never be run > on a machine that needs security of this kind.
While I think it'd be nice to have a boot-time knob for this (a debate that was unsuccessful in earlier threads), I remain skeptical of having a _runtime_ knob for this, as then it becomes a target (and yes, there are plenty of targets, but why add another).
If this was __ro_after_init, maybe that'd be nicer. CONFIG_TRACING=y is used everywhere, so this is really just the whole knob debate over again. Instead, I've been following Linus's distillation of %p usage in the kernel:
http://lkml.kernel.org/r/CA+55aFwQEd_d40g4mUCSsVRZzrFPUJt74vc6PPpb675hYNXcKw@mail.gmail.com
-Kees
-- Kees Cook Pixel Security
| |