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From: Pavel Begunkov <asml.silence@gmail.com>
To: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [BUG] io_uring: defer logic based on shared data
Date: Fri, 25 Oct 2019 12:55:25 +0300	[thread overview]
Message-ID: <5badf1c0-9a7d-0950-2943-ff8db33e0929@gmail.com> (raw)


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I found 2 problems with __io_sequence_defer().

1. it uses @sq_dropped, but doesn't consider @cq_overflow
2. @sq_dropped and @cq_overflow are write-shared with userspace, so
it can be maliciously changed.

see sent liburing test (test/defer *_hung()), which left an unkillable
process for me

-- 
Yours sincerely,
Pavel Begunkov


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             reply	other threads:[~2019-10-25  9:55 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-25  9:55 Pavel Begunkov [this message]
2019-10-25 16:03 ` [BUG] io_uring: defer logic based on shared data Jens Axboe
2019-10-25 16:09   ` Jens Axboe
2019-10-25 16:21     ` Jens Axboe
2019-10-25 16:21   ` Pavel Begunkov
2019-10-25 16:27     ` Jens Axboe
2019-10-25 16:32       ` Jens Axboe
2019-10-25 16:40         ` Pavel Begunkov
2019-10-25 16:44           ` Jens Axboe
2019-10-25 16:55             ` Pavel Begunkov
2019-10-25 16:57               ` Jens Axboe
2019-10-25 18:13                 ` Pavel Begunkov
2019-10-25 18:17                   ` Jens Axboe

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