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Date: Wed, 12 Feb 2025 09:23:26 +0100
Message-Id: <D7QBMEU5WL4L.2FI34UVHXCDC5@bsdbackstore.eu>
Cc: "mgurtovoy" <mgurtovoy@nvidia.com>, "sagi" <sagi@grimberg.me>, "kbusch"
 <kbusch@kernel.org>, "sashal" <sashal@kernel.org>, "linux-kernel"
 <linux-kernel@vger.kernel.org>, "linux-nvme"
 <linux-nvme@lists.infradead.org>, "linux-block"
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Subject: Re: nvme-tcp: fix a possible UAF when failing to send request
From: "Maurizio Lombardi" <mlombard@bsdbackstore.eu>
To: "Maurizio Lombardi" <mlombard@bsdbackstore.eu>,
 "zhang.guanghui@cestc.cn" <zhang.guanghui@cestc.cn>, "chunguang.xu"
 <chunguang.xu@shopee.com>
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In-Reply-To: <D7QBDBZMZTCI.1W40WVL5JJ3O7@bsdbackstore.eu>

On Wed Feb 12, 2025 at 9:11 AM CET, Maurizio Lombardi wrote:
> Hello, could you try this patch?
>
> Concurrent calls to try_recv() should already be protected by
> sock_lock.
>
> +	mutex_lock(&queue->send_mutex);
>  	nvme_tcp_try_recv(queue);
> +	r =3D queue->nr_cqe;
> +	mutex_unlock(&queue->send_mutex);

Well, reading nr_cqe like this is still racy, but should be a minor
issue and not hard to fix.

Maurizio