Re: [PATCH] usb: gadget: aspeed: fix buffer overflow

[Greg Kroah-Hartman]

On Fri, Oct 28, 2022 at 09:55:57AM +0000, Neal Liu wrote:
> > > > > Thanks for your feedback.
> > > > > I tried to reproduce it on my side, and it cannot be reproduce it.
> > > > > Here are my test sequences:
> > > > > 1. emulate one of the vhub port to usb ethernet through Linux
> > > > > gadget
> > > > > (ncm)
> > > >
> > > > We are using rndis instead of ncm.
> > > >
> > > > > 2. connect BMC vhub to Host
> > > > > 3. BMC & Host can ping each other (both usb eth dev default mtu is
> > > > > 1500) 4. Set BMC mtu to 1000 (Host OS cannot set usb eth dev mtu
> > > > > to 2000, it's maxmtu is 1500)
> > > >
> > > > Not sure if it's related, but in my case (USB rndis, Debian 10 OS)
> > > > it should be able to set MTU to 2000.
> > >
> > > Using rndis is able to set MTU to 2000, and the issue can be reproduced.
> > 
> > Please NEVER use rndis anymore.  I need to go just delete that driver from
> > the tree.
> > 
> > It is insecure-by-design and will cause any system that runs it to be instantly
> > compromised and it can not be fixed.  Never trust it.
> > 
> > Even for data throughput tests, I wouldn't trust it as it does odd things with
> > packet sizes as you show here.
> 
> Thanks for the info, Greg.
> If rndis will no longer be supported, how to use usb-ethernet on Windows OS?
> For my understanding, ncm/ecm cannot work on Windows OS.

rndis should ONLY be there for Windows XP, which is long out-of-support.
Newer versions of windows have more sane usb protocols built into it and
this driver is not needed.

As proof of this, Android devices removed this from their kernel
configuration a few years ago and no one has complained :)

thanks,

greg k-h