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Date: Fri, 15 Dec 2023 18:27:24 +0100
From: Greg KH <gregkh@linuxfoundation.org>
To: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: linux-usb@vger.kernel.org, Wendy Wang <wendy.wang@intel.com>
Subject: Re: [PATCH 1/1] xhci: Fix null pointer dereference during S4 resume
 when resetting ep0
Message-ID: <2023121515-paper-annuity-a0e3@gregkh>
References: <20231215125707.1732989-1-mathias.nyman@linux.intel.com>
 <20231215125707.1732989-2-mathias.nyman@linux.intel.com>
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In-Reply-To: <20231215125707.1732989-2-mathias.nyman@linux.intel.com>

On Fri, Dec 15, 2023 at 02:57:07PM +0200, Mathias Nyman wrote:
> During device enumeration usb core resets endpoint 0 if the max packet
> size value differs from the one read from the device descriptor.
> 
> usb core will additionally reset endpoint 0 during S4 resume, before
> re-enumerating the device, if the device has a reset-resume flag set.
> 
> In this case the xhci device representation vdev may be lost due to
> xHC restore error and re-initialization during S4 resume.
> 
> Make sure slot_id and vdev are valid before trying to re-configure max
> packet size during endpoint 0 reset.
> max packet size will be re-configured later during re-enumeration.
> 
> This fixes commit e34900f46cd6 ("xhci: Reconfigure endpoint 0 max packet
> size only during endpoint reset") which is currently in usb-next,
> on its way to 6.7

You mean "6.8" here, right?

thanks,

greg k-h