Re: [PATCH] tty/n_hdlc: fix __might_sleep warning

[Arnd Bergmann]

On Thu, Jan 10, 2019 at 12:39 PM Tetsuo Handa
<penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
> On 2019/01/02 5:28, Paul Fulghum wrote:
> > Fix __might_sleep warning in tty/n_hdlc.c read due to copy_to_user call while current is TASK_INTERRUPTIBLE.
> > This is a false positive since the code path does not depend on current state remaining TASK_INTERRUPTIBLE.
> > The loop breaks out and sets TASK_RUNNING after calling copy_to_user.
> > This patch supresses the warning by setting TASK_RUNNING before calling copy_to_user.
> >
> > [1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324
> >
> > Signed-off-by: Paul Fulghum <paulkf@xxxxxxxxxxxxx>
> > Reported-by: syzbot <syzbot+c244af085a0159d22879@xxxxxxxxxxxxxxxxxxxxxxxxx>
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>

This version looks good to me.

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>

       Arnd