Re: KASAN: use-after-free Write in hci_sock_release

[Dmitry Vyukov]

On Sat, Mar 23, 2019 at 9:25 PM Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote:
>
> On Fri, Mar 22, 2019 at 5:19 AM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> >
> > On Fri, Mar 22, 2019 at 1:04 PM syzbot
> > <syzbot+b364ed862aa07c74bc62@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > syzbot has bisected this bug to:
> > >
> > > commit c470abd4fde40ea6a0846a2beab642a578c0b8cd
> > > Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> > > Date:   Sun Feb 19 22:34:00 2017 +0000
> > >
> > >      Linux 4.10
> > >
> > > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1664c6df200000
> > > start commit:   c470abd4 Linux 4.10
> > > git tree:       upstream
> > > kernel config:  https://syzkaller.appspot.com/x/.config?x=7308e68273924137
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=b364ed862aa07c74bc62
> > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=152532bb400000
> > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13f73320c00000
> > >
> > > Reported-by: syzbot+b364ed862aa07c74bc62@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > Fixes: c470abd4fde4 ("Linux 4.10")
> > >
> > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> >
> > The same story of HCI being broken before v4.10, so this is bisected
> > to the release.
>
> Does syzbot test the latest upstream?

Yes, it does.

> Isn't this supposed to be fixed by
>
> commit e20a2e9c42c9e4002d9e338d74e7819e88d77162
> Author: Myungho Jung <mhjungk@xxxxxxxxx>
> Date:   Sat Feb 2 16:56:36 2019 -0800
>
>     Bluetooth: Fix decrementing reference count twice in releasing socket
>
> ?

I and syzbot have no idea. You may know better. Is it? If yes, please
tell syzbot about the fix.