Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1426836

Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace

Show all headers | View raw

On 06/20, Andy Lutomirski wrote:
>
> On Mon, Jun 20, 2016 at 8:24 AM, Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > How about the simple change below for now? IIRC 32-bit task can't use
> > "syscall" so if syscall_get_nr() >= 0 then even the wrong TS_COMPAT is
> > not that bad, even if it "leaks" to user-mode.
>
> Hmm.  That should fix the minor security issue, but it will even
> further break cross-arch tracing: now a 32-bit tracer tracing a 64-bit
> task that does int $0x80 will malfunction even more than it would
> have.

This is broken in any case. I mean, a 32-bit debugger can't really
debug a 64-bit task.

I don't think this change makes the things really worse.

> Also, it relies on bizarre arch details IMO.

Heh,  it looks as if your patch do not ;)

> I think I prefer my version, coming momentarily.

I disagree... I don't really understand why do we need the additional
complications for the minimal fix which doesn't look very nice anyway.

But I won't argue, and your patch looks correct to me.

Oleg.

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Andy Lutomirski <luto@kernel.org> - 2016-06-18 12:30 +0200
  Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Pedro Alves <pedro@palves.net> - 2016-06-18 16:00 +0200
    Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Pedro Alves <palves@redhat.com> - 2016-06-18 16:50 +0200
    Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Andy Lutomirski <luto@amacapital.net> - 2016-06-18 19:10 +0200
      Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Andy Lutomirski <luto@amacapital.net> - 2016-06-20 00:20 +0200
        Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Pedro Alves <pedro@palves.net> - 2016-06-20 12:30 +0200
        Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in  ptrace Oleg Nesterov <oleg@redhat.com> - 2016-06-20 18:40 +0200
          Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Andy Lutomirski <luto@amacapital.net> - 2016-06-20 18:50 +0200
            Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in  ptrace Oleg Nesterov <oleg@redhat.com> - 2016-06-20 19:20 +0200
              Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Andy Lutomirski <luto@amacapital.net> - 2016-06-20 19:30 +0200
      Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Pedro Alves <pedro@palves.net> - 2016-06-20 12:10 +0200
        Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Jan Kratochvil <jan.kratochvil@redhat.com> - 2016-06-20 13:20 +0200
  Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Kees Cook <keescook@chromium.org> - 2016-06-18 19:50 +0200
  Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Andy Lutomirski <luto@amacapital.net> - 2016-06-20 00:30 +0200
  Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in  ptrace Oleg Nesterov <oleg@redhat.com> - 2016-06-20 00:30 +0200
    Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in ptrace Andy Lutomirski <luto@amacapital.net> - 2016-06-20 08:20 +0200
      Re: [PATCH] x86/ptrace: Remove questionable TS_COMPAT usage in  ptrace Oleg Nesterov <oleg@redhat.com> - 2016-06-20 18:40 +0200
      the usage of __SYSCALL_MASK in entry_SYSCALL_64/do_syscall_64 is not  consistent Oleg Nesterov <oleg@redhat.com> - 2016-06-20 20:10 +0200
        Re: the usage of __SYSCALL_MASK in entry_SYSCALL_64/do_syscall_64 is  not consistent Kees Cook <keescook@chromium.org> - 2016-06-21 21:10 +0200

csiph-web