From patchwork Wed May 4 16:45:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 569896 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 1EDABC433EF for ; Wed, 4 May 2022 16:51:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354211AbiEDQzM (ORCPT ); Wed, 4 May 2022 12:55:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354430AbiEDQyW (ORCPT ); Wed, 4 May 2022 12:54:22 -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 2A8564925C; Wed, 4 May 2022 09:49:31 -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 D865DB82554; Wed, 4 May 2022 16:49:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E1B3C385AA; Wed, 4 May 2022 16:49:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651682968; bh=e559Bqf6LPnE3jwmAkFfShmHGWGViQtRHK3xguGfn7M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JXv9+z4gxvZFprPD9UO9Z0UV/V2mjIRXxUzSS2kdIzkSwu/IKtsxKFY73wakDtrdb xexym6xIUjWBwyGUjAjETJ3UW+zSpY7bNS5ftELKkk07FEAoJYshPFXAQ9BcpBMfUa MAdhajCc3ym8fNffyvwQ9TS/DeSHUNEhDfy+U75M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Starke Subject: [PATCH 5.4 82/84] tty: n_gsm: fix incorrect UA handling Date: Wed, 4 May 2022 18:45:03 +0200 Message-Id: <20220504152933.940828231@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220504152927.744120418@linuxfoundation.org> References: <20220504152927.744120418@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 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 @@ -1813,7 +1813,6 @@ 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;