Re: Please apply "xen-netback: delete NAPI instance when queue fails to initialize" to v4.4.y

[Greg KH]

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@xxxxxxxxx>

What was tested?

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

greg k-h