Re: possible deadlock in acct_pin_kill

[Amir Goldstein]

On Thu, Mar 28, 2019 at 10:23 AM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
>
> On Wed, Mar 27, 2019 at 8:16 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
> >
> > On Wed, Mar 27, 2019 at 5:53 AM syzbot
> > <syzbot+2a73a6ea9507b7112141@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > syzbot has bisected this bug to:
> > >
> > > commit e950564b97fd0f541b02eb207685d0746f5ecf29
> > > Author: Miklos Szeredi <mszeredi@xxxxxxxxxx>
> > > Date:   Tue Jul 24 13:01:55 2018 +0000
> > >
> > >      vfs: don't evict uninitialized inode
> > >
> > > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=12123143200000
> > > start commit:   da5322e6 Merge tag 'selinux-pr-20181115' of git://git.kern..
> > > git tree:       upstream
> > > final crash:    https://syzkaller.appspot.com/x/report.txt?x=11123143200000
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=16123143200000
> > > kernel config:  https://syzkaller.appspot.com/x/.config?x=d86f24333880b605
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=2a73a6ea9507b7112141
> > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12298533400000
> > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17ff545d400000
> > >
> > > Reported-by: syzbot+2a73a6ea9507b7112141@xxxxxxxxxxxxxxxxxxxxxxxxx
> > > Fixes: e950564b97fd ("vfs: don't evict uninitialized inode")
> > >
> > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> >
> > The repro seems fine for catching the subject bug, but I can't get it
> > to reproduce on my system. I have written a simpler reliable repro.
> > Its in the commit message of the patch to test below:
> >
> > #syz test: https://github.com/amir73il/linux.git acct_pin_kill_deadlock
> >
> > I have been pinging Al about the fix above for a while, but no response:
> >
> > https://marc.info/?l=linux-fsdevel&m=155119096826039&w=2
>
> I would ping it as well, but I can't find it in my inbox. Is it on LKML?
>

No. it's scope is linux-fsdevel.

Anyway, this fix by Al is in linux-next now:

#syz fix: acct_on(): don't mess with freeze protection

Thanks,
Amir.