From patchwork Mon Feb 28 17:25:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 546987 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 974FEC4332F for ; Mon, 28 Feb 2022 18:10:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235798AbiB1SLX (ORCPT ); Mon, 28 Feb 2022 13:11:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241589AbiB1SKG (ORCPT ); Mon, 28 Feb 2022 13:10:06 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20C04B8B77; Mon, 28 Feb 2022 09:50:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E7100B81187; Mon, 28 Feb 2022 17:49:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 503D0C340F0; Mon, 28 Feb 2022 17:49:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646070565; bh=dIvtYGL8QlYhrBoDwIohKm7XNDqLVS8u6y7+ggqICO0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0AAVybPo8OUADLrKsgiGnPRjed+3oQsHDbzqo64ahVjZeGsJzvmv/fWP2OMOjZLEc zOuBt5k0SkBeCTY4fdjPmEzAEkMKYb90ii6KBtFwn2s35yMvR/eCm8ejzY35Sg3ftn LiA0cpdqlRWKu3Y8z3M/+0iJx4QAbeoryLwU1BGE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Starke Subject: [PATCH 5.16 156/164] tty: n_gsm: fix proper link termination after failed open Date: Mon, 28 Feb 2022 18:25:18 +0100 Message-Id: <20220228172413.874760607@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220228172359.567256961@linuxfoundation.org> References: <20220228172359.567256961@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: daniel.starke@siemens.com commit e3b7468f082d106459e86e8dc6fb9bdd65553433 upstream. Trying to open a DLCI by sending a SABM frame may fail with a timeout. The link is closed on the initiator side without informing the responder about this event. The responder assumes the link is open after sending a UA frame to answer the SABM frame. The link gets stuck in a half open state. This patch fixes this by initiating the proper link termination procedure after link setup timeout instead of silently closing it down. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke Link: https://lore.kernel.org/r/20220218073123.2121-3-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_gsm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1518,7 +1518,7 @@ static void gsm_dlci_t1(struct timer_lis dlci->mode = DLCI_MODE_ADM; gsm_dlci_open(dlci); } else { - gsm_dlci_close(dlci); + gsm_dlci_begin_close(dlci); /* prevent half open link */ } break;