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 4A9CAC43217 for ; Tue, 10 May 2022 13:23:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243190AbiEJN02 (ORCPT ); Tue, 10 May 2022 09:26:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243560AbiEJNWE (ORCPT ); Tue, 10 May 2022 09:22:04 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1ECCA53A44; Tue, 10 May 2022 06:16:20 -0700 (PDT) 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 47C65B81DA3; Tue, 10 May 2022 13:16:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8DCD2C385A6; Tue, 10 May 2022 13:16:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652188576; bh=JJe8sEvxS5e9xUkxokihEGFI8ATuPtWVWFYdW0GQdmI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tMRrb0d1sEUFRA2c4bvzVkRGuxfwxmAiFSHYXdoy+YR+LOHTTBmgJGMPgrJ7Twxuo vPJEEjpx+/GG1lk0Pf4XWRQZ6dOUvnX/NF+9qkWrMZ4icaTZqp9D0fcF6dhO2XrVic jd0+YVmK9+Ilu9WCEl+6bT4g6428c/UMQwIpfykU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Starke Subject: [PATCH 4.14 52/78] tty: n_gsm: fix incorrect UA handling Date: Tue, 10 May 2022 15:07:38 +0200 Message-Id: <20220510130734.079029094@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220510130732.522479698@linuxfoundation.org> References: <20220510130732.522479698@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 commit ff9166c623704337bd6fe66fce2838d9768a6634 upstream. n_gsm is based on the 3GPP 07.010 and its newer version is the 3GPP 27.010. See https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.4.4.2 states that any received unnumbered acknowledgment (UA) with its poll/final (PF) bit set to 0 shall be discarded. Currently, all UA frame are handled in the same way regardless of the PF bit. This does not comply with the standard. Remove the UA case in gsm_queue() to process only UA frames with PF bit set to 1 to abide the standard. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Cc: stable@vger.kernel.org Signed-off-by: Daniel Starke Link: https://lore.kernel.org/r/20220414094225.4527-20-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_gsm.c | 1 - 1 file changed, 1 deletion(-) --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1825,7 +1825,6 @@ static void gsm_queue(struct gsm_mux *gs gsm_response(gsm, address, UA); gsm_dlci_close(dlci); break; - case UA: case UA|PF: if (cr == 0 || dlci == NULL) break;