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 D246DC433F5 for ; Mon, 28 Feb 2022 17:28:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234588AbiB1R3Q (ORCPT ); Mon, 28 Feb 2022 12:29:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235836AbiB1R1v (ORCPT ); Mon, 28 Feb 2022 12:27:51 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCE3889CCB; Mon, 28 Feb 2022 09:26:57 -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 3945AB815B4; Mon, 28 Feb 2022 17:26:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93E9CC340E7; Mon, 28 Feb 2022 17:26:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646069214; bh=KcD0VeXis5K6pfFfjojtXd9veRqSBEP7ZPOuwSBvwoU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qq+ZBdj5rE+RSShgBsXzS6UYzE6JSwhBAzJLjnkngNym/bW7TwbcTORviIfa5lMwO LGYAis/fQXQM4Gdv6t6aXpyJ2mHKm4q2YiLJXBUZ6EKVzchwSy3Km73+g+nUPTGQN9 5m0Lw5NekWo5SWBSRpumwXi3fEYy+1d5SgF1/aAo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Starke Subject: [PATCH 4.9 27/29] tty: n_gsm: fix proper link termination after failed open Date: Mon, 28 Feb 2022 18:23:54 +0100 Message-Id: <20220228172144.391709007@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220228172141.744228435@linuxfoundation.org> References: <20220228172141.744228435@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -1506,7 +1506,7 @@ static void gsm_dlci_t1(unsigned long da dlci->mode = DLCI_MODE_ADM; gsm_dlci_open(dlci); } else { - gsm_dlci_close(dlci); + gsm_dlci_begin_close(dlci); /* prevent half open link */ } break;