Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933204Ab1EROfU (ORCPT ); Wed, 18 May 2011 10:35:20 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:52073 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933044Ab1EROfT (ORCPT ); Wed, 18 May 2011 10:35:19 -0400 Date: Wed, 18 May 2011 15:36:36 +0100 From: Alan Cox To: Jiri Olsa Cc: Alan Cox , Frederic Weisbecker , Kay Sievers , Greg Kroah-Hartman , Arnd Bergmann , LKML Subject: Re: BUG: NULL pointer deref in tty port / uart Message-ID: <20110518153636.5cdcdd78@lxorguk.ukuu.org.uk> In-Reply-To: <20110518142631.GB2011@jolsa.brq.redhat.com> References: <20110517231229.GB1776@nowhere> <20110518004420.2b8f5da9@bob.linux.org.uk> <20110518142631.GB2011@jolsa.brq.redhat.com> X-Mailer: Claws Mail 3.7.8 (GTK+ 2.22.0; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 842 Lines: 20 > have the same issue.. looks like we should not NULL the port->tty > if there's blocked open, but not sure what's exactly the logic > behind "port's block_open and count" .. A pending open is not a user of the tty as far as the rest of the stack is concerned. I also don't see why clearing port->tty is causing this crash because nothing on that path should ever be going via port->tty and it isn't safe to do so. > attached patch fixes it for me But still breaks on hangup where we can't do that. Where is port->tty getting misused to cause the crash, that is the bit I'm missing somewhere. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/