Subject: Re: [PATCH v3 0/5] aio: fix use-after-free and missing wakeups
To:     Linus Torvalds <torvalds@linux-foundation.org>,
        Eric Biggers <ebiggers@kernel.org>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Benjamin LaHaise <bcrl@kvack.org>, linux-aio@kvack.org,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Ramji Jiyani <ramjiyani@google.com>,
        Christoph Hellwig <hch@lst.de>,
        Oleg Nesterov <oleg@redhat.com>,
        Martijn Coenen <maco@android.com>,
        stable <stable@vger.kernel.org>
References: <20211209010455.42744-1-ebiggers@kernel.org>
 <CAHk-=wjkXez+ugCbF3YpODQQS-g=-4poCwXaisLW4p2ZN_=hxw@mail.gmail.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <4a472e72-d527-db79-d46e-efa9d4cad5bb@kernel.dk>
Date:   Thu, 9 Dec 2021 14:46:45 -0700
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On 12/9/21 11:00 AM, Linus Torvalds wrote:
> On Wed, Dec 8, 2021 at 5:06 PM Eric Biggers <ebiggers@kernel.org> wrote:
>>
>> Careful review is appreciated; the aio poll code is very hard to work
>> with, and it doesn't appear to have many tests.  I've verified that it
>> passes the libaio test suite, which provides some coverage of poll.
>>
>> Note, it looks like io_uring has the same bugs as aio poll.  I haven't
>> tried to fix io_uring.
> 
> I'm hoping Jens is looking at the io_ring case, but I'm also assuming
> that I'll just get a pull request for this at some point.

Yes, when I saw this original posting I did discuss it with Pavel as
well, and we agree that the same issue exists there. Which isn't too
surprising, as that's where the io_uring poll code from originally.

Eric, do you have a test case for this? aio is fine, we can convert it
to io_uring as well. Would be nice for both verifying the fix, but also
to carry in the io_uring regression tests for the future.

-- 
Jens Axboe