From: Stefano Garzarella <sgarzare@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: syzbot <syzbot+3c23789ea938faaef049@syzkaller.appspotmail.com>,
io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
viro@zeniv.linux.org.uk
Subject: Re: INFO: task hung in io_sq_thread_stop
Date: Wed, 9 Sep 2020 17:07:27 +0200 [thread overview]
Message-ID: <20200909150727.wbatiuzl3o6u3vgo@steredhat> (raw)
In-Reply-To: <fa8f11bf-d0e6-42b9-0a2e-2bb4c8679b99@kernel.dk>
On Wed, Sep 09, 2020 at 08:03:32AM -0600, Jens Axboe wrote:
> On 9/9/20 4:03 AM, Stefano Garzarella wrote:
> > On Wed, Sep 09, 2020 at 01:49:22AM -0700, syzbot wrote:
> >> Hello,
> >>
> >> syzbot found the following issue on:
> >>
> >> HEAD commit: dff9f829 Add linux-next specific files for 20200908
> >> git tree: linux-next
> >> console output: https://syzkaller.appspot.com/x/log.txt?x=112f880d900000
> >> kernel config: https://syzkaller.appspot.com/x/.config?x=37b3426c77bda44c
> >> dashboard link: https://syzkaller.appspot.com/bug?extid=3c23789ea938faaef049
> >> compiler: gcc (GCC) 10.1.0-syz 20200507
> >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17c082a5900000
> >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1474f5f9900000
> >>
> >> Bisection is inconclusive: the first bad commit could be any of:
> >>
> >> d730b1a2 io_uring: add IOURING_REGISTER_RESTRICTIONS opcode
> >> 7ec3d1dd io_uring: allow disabling rings during the creation
> >
> > I'm not sure it is related, but while rebasing I forgot to update the
> > right label in the error path.
> >
> > Since the check of ring state is after the increase of ctx refcount, we
> > need to decrease it jumping to 'out' label instead of 'out_fput':
> > diff --git a/fs/io_uring.c b/fs/io_uring.c
> > index d00eb6bf6ce9..f35da516095a 100644
> > --- a/fs/io_uring.c
> > +++ b/fs/io_uring.c
> > @@ -8649,7 +8649,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
> > goto out_fput;
> >
> > if (ctx->flags & IORING_SETUP_R_DISABLED)
> > - goto out_fput;
> > + goto out;
> >
> > /*
> > * For SQ polling, the thread will do all submissions and completions.
> >
> > I'll send a patch ASAP and check if it solves this issue.
>
> I think that's a separate bug, it's definitely a bug. So please do send
> the fix, thanks.
>
Sure I'm sending it!
Thanks,
Stefano
next prev parent reply other threads:[~2020-09-09 17:19 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-09 8:49 INFO: task hung in io_sq_thread_stop syzbot
2020-09-09 10:03 ` Stefano Garzarella
2020-09-09 14:03 ` Jens Axboe
2020-09-09 15:07 ` Stefano Garzarella [this message]
[not found] ` <20200909134317.19732-1-hdanton@sina.com>
2020-09-09 14:05 ` Jens Axboe
2020-09-09 15:32 ` Stefano Garzarella
2020-10-30 10:06 ` Dmitry Vyukov
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