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Date:   Wed, 24 Feb 2021 18:21:09 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     SeongJae Park <sjpark@amazon.com>
Cc:     sashal@kernel.org, aams@amazon.com, markubo@amazon.com,
        linux-kernel@vger.kernel.org,
        "# 4 . 4 . y" <stable@vger.kernel.org>,
        David Vrabel <david.vrabel@citrix.com>,
        "David S . Miller" <davem@davemloft.net>
Subject: Re: Please apply "xen-netback: delete NAPI instance when queue fails
 to initialize" to v4.4.y
Message-ID: <YDaLBcj5DJrSWXqU@kroah.com>
References: <20210224170356.20697-1-sjpark@amazon.com>
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On Wed, Feb 24, 2021 at 06:03:56PM +0100, SeongJae Park wrote:
> This is a request for merge of upstream commit 4a658527271b ("xen-netback:
> delete NAPI instance when queue fails to initialize") on v4.4.y tree.
> 
> If 'xenvif_connect()' fails after successful 'netif_napi_add()', the napi is
> not cleaned up.  Because 'create_queues()' frees the queues in its error
> handling code, if the 'xenvif_free()' is called for the vif, use-after-free
> occurs. The upstream commit fixes the problem by cleaning up the napi in the
> 'xenvif_connect()'.
> 
> Attaching the original patch below for your convenience.

The original patch does not apply cleanly.

> Tested-by: Markus Boehme <markubo@amazon.de>

What was tested?

I backported the patch, but next time, please provide the patch that
will work properly.

greg k-h