Re: A potential race in drivers/staging/speakup/speakup.ko

[Pavel Andrianov]

05.09.2016 12:43, Samuel Thibault ÐÐÑÐÑ:
> Hello,
>
> Pavel Andrianov, on Mon 05 Sep 2016 11:51:50 +0300, wrote:
> > There is a potential race in drivers/staging/speakup/speakup.ko.
> > All operations with global pointers buff_in and buff_out are performed
> > without any locks. Thus, a simultaneous write (via synth_buffer_clear or
> > synth_buffer_add) to the pointers may lead to inconsistent data.
> >
> > Should a local lock be used here?
>
> AIUI, all callers of these functions have speakup_info.spinlock held.
>
> Samuel

Regard a call stack

-> synth_direct_store
  -> synth_printf
    -> synth_buffer_add

The functions have not held speakup_info.spinlock.

--
Pavel Andrianov
Linux Verification Center, ISPRAS
web: http://linuxtesting.org
e-mail: andrianov@xxxxxxxxx