Re: [PATCH] net: hso: fix NULL-deref on disconnect regression

From: Greg Kroah-Hartman
Date: Mon Apr 26 2021 - 05:50:53 EST


On Mon, Apr 26, 2021 at 11:35:46AM +0200, Johan Hovold wrote:
> On Mon, Apr 26, 2021 at 11:29:11AM +0200, Leonardo Antoniazzi wrote:
> > On Mon, 26 Apr 2021 10:11:49 +0200
> > Johan Hovold <johan@xxxxxxxxxx> wrote:
> >
> > > Commit 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device
> > > unregistration") fixed the racy minor allocation reported by syzbot, but
> > > introduced an unconditional NULL-pointer dereference on every disconnect
> > > instead.
> > >
> > > Specifically, the serial device table must no longer be accessed after
> > > the minor has been released by hso_serial_tty_unregister().
> > >
> > > Fixes: 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration")
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Cc: Anirudh Rayabharam <mail@xxxxxxxxxxxxx>
> > > Reported-by: Leonardo Antoniazzi <leoanto@xxxxxxxx>
> > > Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> > > ---
>
> > the patch fix the problem
>
> Thanks for confirming.
>
> Next time, please keep the CC list intact when replying so that everyone
> sees that you've tested it.

Wonderful. Johan, thanks for the quick fix.

netdev maintainers, mind if I take this fix through my tree to Linus
this week, or can you all get it to him before -rc1 through the
networking tree?

thanks,

greg k-h