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Subject: Re: [PATCH] io_uring: fix fs cleanup on cqe overflow
To:     Pavel Begunkov <asml.silence@gmail.com>, io-uring@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <72e624af63743f265e25da90c322bd45b9d4feeb.1586409373.git.asml.silence@gmail.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <b8571766-1ae3-00e5-045d-6b7d5ef2c72b@kernel.dk>
Date:   Thu, 9 Apr 2020 08:37:34 -0700
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On 4/8/20 10:17 PM, Pavel Begunkov wrote:
> If completion queue overflow happened, __io_cqring_fill_event() will
> update req->cflags, which is in a union with req->work and happend to
> be aliased to req->work.fs. Following io_free_req() ->
> io_req_work_drop_env() may get a bunch of different problems (miscount
> fs->users, segfault, etc) on cleaning @fs.

Good catch, applied.

-- 
Jens Axboe