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References: <20210806121521.124365-1-xianting.tian@linux.alibaba.com>
In-Reply-To: <20210806121521.124365-1-xianting.tian@linux.alibaba.com>
From:   Jassi Brar <jassisinghbrar@gmail.com>
Date:   Mon, 16 Aug 2021 23:29:59 -0500
Message-ID: <CABb+yY3i5aZQrimoWLTMQRY5WsOJ1FCGNxBN0Hz_=4qxUvoqSw@mail.gmail.com>
Subject: Re: [PATCH] mailbox: fix a UAF bug in msg_submit()
To:     Xianting Tian <xianting.tian@linux.alibaba.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        guoren@kernel.org
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On Fri, Aug 6, 2021 at 7:15 AM Xianting Tian
<xianting.tian@linux.alibaba.com> wrote:
>
> We met a UAF issue during our mailbox testing.
>
> In synchronous mailbox, we use mbox_send_message() to send a message
> and wait for completion. mbox_send_message() calls msg_submit() to
> send the message for the first time, if timeout, it will send the
> message in tx_tick() for the second time.
>
Seems like your controller's  .send_data() returns error. Can you
please explain why it does so? Because
send_data() only _accepts_ data for further transmission... which
should seldom be a problem.

thanks.