linux-kernel - Re: [syzbot] INFO: task hung in fuse_simple

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Date:   Fri, 6 Aug 2021 11:34:43 +0200
From:   Miklos Szeredi <miklos@...redi.hu>
To:     Dmitry Vyukov <dvyukov@...gle.com>
Cc:     syzbot <syzkaller@...glegroups.com>,
        syzbot <syzbot+46fe899420456e014d6b@...kaller.appspotmail.com>,
        areeba.ahmed@...uregulfpak.com, linux-fsdevel@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        syzkaller-bugs <syzkaller-bugs@...glegroups.com>
Subject: Re: [syzbot] INFO: task hung in fuse_simple_request

On Fri, 6 Aug 2021 at 11:15, Dmitry Vyukov <dvyukov@...gle.com> wrote:
>
> ",On Fri, 6 Aug 2021 at 10:54, Miklos Szeredi <miklos@...redi.hu> wrote:
> >
> > Hi,
> >
> > I'm not sure what to make of this report.
> >
> > Does syzbot try to kill all tasks before generating such a hung task report?
> >
> > Does it use the fuse specific /sys/fs/fuse/connections/*/abort to
> > terminate stuck filesystems?
>
> Hi Miklos,
>
> Grepping the C reproducer for "/sys/fs/fuse/connections", it seems
> that it tries to abort all connections.

Hi  Dmitry,

So this could indicate a bug in the abort code of fuse, or it could
indicate that the test case DoS-es the system so that the abort code
simply doesn't get the resources to execute.

Can the two be differentiated somehow?

Thanks,
Miklos