On Sat, 22 Sep 2018, Peter Zijlstra wrote:
> On Sat, Sep 22, 2018 at 11:53:14AM +0200, Thomas Gleixner wrote:
> > +bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode)
> > +{
> > + struct mm_struct *mm;
> > + int res;
> > +
> > + res = __ptrace_may_access_basic(task, mode);
> > + if (res <= 0)
> > + return !res;
> > +
> > + rcu_read_lock();
> > + res = __ptrace_may_access_cred(__task_cred(task), mode);
> > rcu_read_unlock();
> > + if (res)
> > + return false;
> > +
> > + mm = task->mm;
> > + if (mm && get_dumpable(mm) != SUID_DUMP_USER)
> > + return false;
> > + return true;
> > +}
> > +
> > +/* Returns 0 on success, -errno on denial. */
> > +static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
> > +{
> > + const struct cred *tcred;
> > + struct mm_struct *mm;
> > + int res;
> > +
> > + res = __ptrace_may_access_basic(task, mode);
> > + if (res <= 0)
> > + return res;
> > +
> > + rcu_read_lock();
> > + tcred = __task_cred(task);
> > + res = __ptrace_may_access_cred(tcred, mode);
> > + if (res > 0)
> > + res = ptrace_has_cap(tcred->user_ns, mode) ? 0 : -EPERM;
> > rcu_read_unlock();
> > + if (res < 0)
> > + return res;
> > +
> > mm = task->mm;
> > + if (mm && (get_dumpable(mm) != SUID_DUMP_USER &&
> > + !ptrace_has_cap(mm->user_ns, mode)))
> > + return -EPERM;
> >
> > return security_ptrace_access_check(task, mode);
> > }
>
> This has some unfortunate duplication.
>
> Lets go with it for now, but I'll see if I can do something about that
> later.
Yes, I know. I tried to make the duplication smaller, but all attempts
ended up being a convoluted mess. I'll try again after applying more
coffee.
Thanks,
tglx
