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 2A32EC3527D for ; Wed, 4 May 2022 17:17:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358004AbiEDRUN (ORCPT ); Wed, 4 May 2022 13:20:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358179AbiEDRPo (ORCPT ); Wed, 4 May 2022 13:15:44 -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 1EDA356422; Wed, 4 May 2022 09:59:26 -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 E666AB82737; Wed, 4 May 2022 16:59:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7ECBBC385A5; Wed, 4 May 2022 16:59:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651683563; bh=1uPF9iPeVnkugtdDgv3+RKTt3xBCZr5qK5UDqcizsRk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nocz6JQgrPRNrDySsJMCrC4fItPrMolqyT1lgWQzz0ZN5sGSXku6Ql05oKAVtkx5J GTv8lHkxiDDdykJmsqlM17rvPttXAUKgzTwK4QAnS5LPIZOmlJOUyJqivS6BVCwhNO b3PTlCiQM9ofPz4eqyf4yylkQIe1knli8f4e49bY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Starke Subject: [PATCH 5.17 217/225] tty: n_gsm: fix incorrect UA handling Date: Wed, 4 May 2022 18:47:35 +0200 Message-Id: <20220504153129.286283053@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220504153110.096069935@linuxfoundation.org> References: <20220504153110.096069935@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: stable@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 @@ -1865,7 +1865,6 @@ static void gsm_queue(struct gsm_mux *gs } } break; - case UA: case UA|PF: if (cr == 0 || dlci == NULL) break;