Messages in this thread | | | Date | Sat, 22 Sep 2018 16:31:27 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v6 0/3] Harden spectrev2 userspace-userspace protection |
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On Sat, Sep 22, 2018 at 03:30:07PM +0200, Thomas Gleixner wrote: > On Sat, 22 Sep 2018, Thomas Gleixner wrote: > > On Sat, 22 Sep 2018, Peter Zijlstra wrote: > > > 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. > > Lunch and coffee indeed made brain work better. The simple solution was way > too obvious. > --- a/kernel/ptrace.c > +++ b/kernel/ptrace.c > @@ -261,6 +261,9 @@ static int ptrace_check_attach(struct ta > > static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode) > { > + if (mode & PTRACE_MODE_SCHED) > + return false; > + > if (mode & PTRACE_MODE_NOAUDIT) > return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE); > else > @@ -328,9 +331,16 @@ static int __ptrace_may_access(struct ta > !ptrace_has_cap(mm->user_ns, mode))) > return -EPERM; > > + if (mode & PTRACE_MODE_SCHED) > + return 0; > return security_ptrace_access_check(task, mode); > } > > +bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode) > +{ > + return __ptrace_may_access(task, mode | PTRACE_MODE_SCHED); > +}
Ha!, much nicer. Thanks!
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