Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 25 Feb 2022 09:53:35 +0100
From:   "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
To:     "stern@rowland.harvard.edu" <stern@rowland.harvard.edu>
Cc:     "Zhang, Qiang1" <qiang1.zhang@intel.com>,
        Tejun Heo <tj@kernel.org>,
        syzbot <syzbot+348b571beb5eeb70a582@syzkaller.appspotmail.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "syzkaller-bugs@googlegroups.com" <syzkaller-bugs@googlegroups.com>,
        "balbi@kernel.org" <balbi@kernel.org>
Subject: Re: [syzbot] KASAN: use-after-free Read in dev_uevent
Message-ID: <YhiZDy+y1/YmlWL2@kroah.com>
References: <PH0PR11MB58805E3C4CF7D4C41D49BFCFDA3C9@PH0PR11MB5880.namprd11.prod.outlook.com>
 <YhYafwiwUV2Sbn5t@kroah.com>
 <YhZG3GJb8G7oL7l7@rowland.harvard.edu>
 <YhZaDGeIIvpILdCk@kroah.com>
 <YhZiMHHjrBw8am5g@rowland.harvard.edu>
 <PH0PR11MB5880D7544442B4D60810F0D2DA3D9@PH0PR11MB5880.namprd11.prod.outlook.com>
 <PH0PR11MB588091026B817203C772B264DA3D9@PH0PR11MB5880.namprd11.prod.outlook.com>
 <Yhf3ThBfjWVcYszC@rowland.harvard.edu>
 <YhgIs6FmBJYXiQVw@kroah.com>
 <Yhg5lWdEy2G4SsFr@rowland.harvard.edu>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Yhg5lWdEy2G4SsFr@rowland.harvard.edu>
Precedence: bulk

On Thu, Feb 24, 2022 at 09:06:13PM -0500, stern@rowland.harvard.edu wrote:
> On Thu, Feb 24, 2022 at 11:37:39PM +0100, gregkh@linuxfoundation.org wrote:
> > On Thu, Feb 24, 2022 at 04:23:26PM -0500, stern@rowland.harvard.edu wrote:
> > > Can you tell us how this should be fixed?
> > 
> > It should be fixed by properly using the driver core to bind/unbind the
> > driver to devices like I mentioned previously :)
> 
> This would involve creating a "gadget" bus_type (or should it be a 
> device_type under the platform bus?) and registering the gadgets 
> on it, right?.

Yes.  Or you can use the aux bus for this, which might be easier.

> Similarly, the gadget drivers would be registered on 
> this bus.  I suppose we can control which drivers get bound to which 
> gadgets with careful matching code.

The aux bus might make this easier:
	Documentation/driver-api/auxiliary_bus.rst

thanks,

greg k-h