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Subject: Re: [PATCH] io_uring: Fix use-after-free in io_sq_wq_submit_work()
To:     Guoyu Huang <hgy5945@gmail.com>, viro@zeniv.linux.org.uk
Cc:     linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20200805034042.GA29805@ubuntu>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <f4e1b9ee-1b13-9862-8df8-cdad62821715@kernel.dk>
Date:   Wed, 5 Aug 2020 13:10:54 -0600
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On 8/4/20 9:40 PM, Guoyu Huang wrote:
> when ctx->sqo_mm is zero, io_sq_wq_submit_work() frees 'req'
> without deleting it from 'task_list'. After that, 'req' is
> accessed in io_ring_ctx_wait_and_kill() which lead to
> a use-after-free.

This looks like an old one, that affects 5.4 only. I've massaged
it to apply on top of another fix, will ask to get it queued up for
stable. Thanks!

-- 
Jens Axboe