Re: [PATCH v2] Add kernel config option for fuzz testing.

From: Peter Zijlstra
Date: Fri Mar 13 2020 - 04:31:38 EST


On Thu, Mar 12, 2020 at 06:29:35PM -0400, Steven Rostedt wrote:
> > @@ -705,10 +706,12 @@ static void lockdep_print_held_locks(struct task_struct *p)
> > * It's not reliable to print a task's held locks if it's not sleeping
> > * and it's not the current task.
> > */
> > - if (p->state == TASK_RUNNING && p != current)
> > - return;
> > + unreliable = p->state == TASK_RUNNING && p != current;
> > for (i = 0; i < depth; i++) {
> > - printk(" #%d: ", i);
> > + if (unreliable)
> > + printk(" #%d?: ", i);
> > + else
> > + printk(" #%d: ", i);
>
> Have you tried submitting this? Has Peter nacked it?

It has definite UaF potential... do we have a boot parameter that
signals the willingness to trade safetly for more debug output?

Over all, the risk of this going *bang* is quite low I think.