From patchwork Thu Apr 14 09:42:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "D. Starke" X-Patchwork-Id: 561405 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 01524C433F5 for ; Thu, 14 Apr 2022 09:46:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231447AbiDNJsm (ORCPT ); Thu, 14 Apr 2022 05:48:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241974AbiDNJqn (ORCPT ); Thu, 14 Apr 2022 05:46:43 -0400 X-Greylist: delayed 60 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 14 Apr 2022 02:44:01 PDT Received: from mta-64-228.siemens.flowmailer.net (mta-64-228.siemens.flowmailer.net [185.136.64.228]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7B4A7004C for ; Thu, 14 Apr 2022 02:44:01 -0700 (PDT) Received: by mta-64-228.siemens.flowmailer.net with ESMTPSA id 202204140942543e580eba70988bc664 for ; Thu, 14 Apr 2022 11:42:59 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=daniel.starke@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc:References:In-Reply-To; bh=d8jKoM9faKsGDQmqC/btc4Rd+AthsQGvuIMNUMeUktA=; b=bnygzUD5p6LhzJ+6pWthHULcIJN48ylDv+Bvyl3FblVIRF+VXzJZnTWUwOH9Z3OZSE1tYH eyViCjnp2AZY4wZ8Nled9dCfHdzJlMDgDkDECHEfBYhYf88iOopLiNRbR8LYUc0rVNkwp70E LQqN0n4ufysRsTKmPQ7V+5Hipcxss=; From: "D. Starke" To: linux-serial@vger.kernel.org, gregkh@linuxfoundation.org, jirislaby@kernel.org Cc: linux-kernel@vger.kernel.org, Daniel Starke Subject: [PATCH 20/20] tty: n_gsm: fix incorrect UA handling Date: Thu, 14 Apr 2022 02:42:25 -0700 Message-Id: <20220414094225.4527-20-daniel.starke@siemens.com> In-Reply-To: <20220414094225.4527-1-daniel.starke@siemens.com> References: <20220414094225.4527-1-daniel.starke@siemens.com> MIME-Version: 1.0 X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-314044:519-21489:flowmailer Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org From: Daniel Starke 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 --- drivers/tty/n_gsm.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 1905a0fea89b..cf861598a646 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1871,7 +1871,6 @@ static void gsm_queue(struct gsm_mux *gsm) } } break; - case UA: case UA|PF: if (cr == 0 || dlci == NULL) break;