Return-Path: Message-ID: <4A6D91D7.6030204@hartkopp.net> Date: Mon, 27 Jul 2009 13:39:03 +0200 From: Oliver Hartkopp MIME-Version: 1.0 To: Dave Young CC: Alan Cox , Marcel Holtmann , Linux Netdev List , linux-bluetooth@vger.kernel.org Subject: Re: tty_register_device NULL pointer dereference in 2.6.31-rc4 References: <4A6AD807.6060706@hartkopp.net> <20090725115011.7ddf8d00@lxorguk.ukuu.org.uk> <1248520053.28545.156.camel@violet> <20090725131046.0f076f37@lxorguk.ukuu.org.uk> <20090727095904.GA5442@darkstar> <4A6D8BA3.3030601@hartkopp.net> In-Reply-To: <4A6D8BA3.3030601@hartkopp.net> Content-Type: text/plain; charset=us-ascii List-ID: Oliver Hartkopp wrote: > Dave Young wrote: >> On Sat, Jul 25, 2009 at 01:10:46PM +0100, Alan Cox wrote: >>>>> tty_register_device appears to have been called with a NULL pointer. Not >>>>> sure why however. >>>> if that is the pointer for the struct device, then that used to be fine >>>> in the past. Not all RFCOMM device have a parent when they are created. >>> The tty layer doesn't care about the struct device really. Nothing there >>> has changed. The NULL passed appears to be the driver argument. >> Agree with you, because in rfcomm_init, rfcomm thread run before tty initilized, the following patch may fix the problem. >> oliver, could you verify it it fix your problem? > > Hi Dave, > > i get this problem really seldom on my Laptop and i did not manage to get a > reproducible Oops of that problem. > > Anyway the code you are pointing to seems to have a problem and your added > error handling looks good to me - even if i don't know if the initializations > can be reordered in that way. > > I'll try your patch, but it could take a *long* time to prove it right ;-) > Just FYI: Your patch compiled, the system booted without problems and nothing is broken so far. I checked the BT, WLAN and BT dial-up with success. So it looks good to me. Regards, Oliver