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From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Fri, 20 May 2022 10:41:16 +0200
Message-ID: <CACT4Y+bNGPfF-z-9fxCXQO7huMJ=yCknWm_-H=7CJNvKOne3qA@mail.gmail.com>
Subject: Re: [syzbot] general protection fault in __io_arm_poll_handler
To:     Jens Axboe <axboe@kernel.dk>
Cc:     syzbot <syzbot+ba74b85fa15fd7a96437@syzkaller.appspotmail.com>,
        asml.silence@gmail.com, io-uring@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
        syzkaller <syzkaller@googlegroups.com>
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On Sat, 4 Sept 2021 at 02:49, Jens Axboe <axboe@kernel.dk> wrote:
>
> On 9/3/21 5:47 PM, syzbot wrote:
> > Hello,
> >
> > syzbot has tested the proposed patch and the reproducer did not trigger any issue:
> >
> > Reported-and-tested-by: syzbot+ba74b85fa15fd7a96437@syzkaller.appspotmail.com
> >
> > Tested on:
> >
> > commit:         31efe48e io_uring: fix possible poll event lost in mul..
> > git tree:       git://git.kernel.dk/linux-block for-5.15/io_uring
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=914bb805fa8e8da9
> > dashboard link: https://syzkaller.appspot.com/bug?extid=ba74b85fa15fd7a96437
> > compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
> >
> > Note: testing is done by a robot and is best-effort only.
>
> Dmitry, I wonder if there's a way to have syzbot know about what it's
> testing and be able to run the pending patches for that tree? I think
> we're up to 4 reports now that are all just fallout from the same bug,
> and where a patch has been queued up for a few days. Since they all look
> different, I can't fault syzbot for thinking they are different, even if
> they have the same root cause.
>
> Any way we can make this situation better? I can't keep replying that we
> should test the current branch, and it'd be a shame to have a ton of
> dupes.

Hi Jens,

This somehow fell through the cracks, but better late than never.

We could set up a syzbot instance for the io-uring tree.
It won't solve the problem directly, but if the branch contains both
new development ("for-next") and fixes, it will have good chances of
discovering issues before they reach mainline and spread to other
trees.
Do you think it's a good idea? Is there a branch that contains new
development and fixes?