From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED825C25B6B for ; Thu, 26 Oct 2023 08:27:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230283AbjJZI1o (ORCPT ); Thu, 26 Oct 2023 04:27:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229639AbjJZI1n (ORCPT ); Thu, 26 Oct 2023 04:27:43 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A8ABB8; Thu, 26 Oct 2023 01:27:42 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 520FCC433C8; Thu, 26 Oct 2023 08:27:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698308861; bh=cHwm43gql1hfewW6pZ04oWSAGFpGE+sNl6YJbfSjVeg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RFJSc0kp4TMTuN+42N9GVaWO6LDeJgrYEh6/lcxK8CDpO3S3owIW9Dr6+02KY5v3K 7M2aLuv0KD3ntTUc5MVIfQIQCLyFZ0sDqpXwfVNZmto9jNi866n0EOsSNATSEq0Z9A 1d8OSCpkj4m3Xa6ce4W/XUinBKP3Xl1COHon2bLU= Date: Thu, 26 Oct 2023 10:27:37 +0200 From: Greg KH To: "D. Starke" Cc: linux-serial@vger.kernel.org, jirislaby@kernel.org, ilpo.jarvinen@linux.intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] tty: n_gsm: fix race condition in status line change on dead connections Message-ID: <2023102629-onward-bust-d049@gregkh> References: <20231026055844.3127-1-daniel.starke@siemens.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231026055844.3127-1-daniel.starke@siemens.com> Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Thu, Oct 26, 2023 at 07:58:43AM +0200, D. Starke wrote: > From: Daniel Starke > > gsm_cleanup_mux() cleans up the gsm by closing all DLCIs, stopping all > timers, removing the virtual tty devices and clearing the data queues. > This procedure, however, may cause subsequent changes of the virtual modem > status lines of a DLCI. More data is being added the outgoing data queue > and the deleted kick timer is restarted to handle this. At this point many > resources have already been removed by the cleanup procedure. Thus, a > kernel panic occurs. > > Fix this by proving in gsm_modem_update() that the cleanup procedure has > not been started and the mux is still alive. > > Note that writing to a virtual tty is already protected by checks against > the DLCI specific connection state. > > Fixes: c568f7086c6e ("tty: n_gsm: fix missing timer to handle stalled links") > Signed-off-by: Daniel Starke > --- > drivers/tty/n_gsm.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c > index 1f3aba607cd5..0ee7531c9201 100644 > --- a/drivers/tty/n_gsm.c > +++ b/drivers/tty/n_gsm.c > @@ -4108,6 +4108,8 @@ static int gsm_modem_upd_via_msc(struct gsm_dlci *dlci, u8 brk) > > static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk) > { > + if (dlci->gsm->dead) > + return -EL2HLT; > if (dlci->adaption == 2) { > /* Send convergence layer type 2 empty data frame. */ > gsm_modem_upd_via_data(dlci, brk); > -- > 2.34.1 > Hi, This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree. You are receiving this message because of the following common error(s) as indicated below: - You have marked a patch with a "Fixes:" tag for a commit that is in an older released kernel, yet you do not have a cc: stable line in the signed-off-by area at all, which means that the patch will not be applied to any older kernel releases. To properly fix this, please follow the documented rules in the Documentation/process/stable-kernel-rules.rst file for how to resolve this. If you wish to discuss this problem further, or you have questions about how to resolve this issue, please feel free to respond to this email and Greg will reply once he has dug out from the pending patches received from other developers. thanks, greg k-h's patch email bot