From nobody Tue Dec 16 11:42:53 2025 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 4A897C28B2B for ; Fri, 19 Aug 2022 16:34:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352859AbiHSQel (ORCPT ); Fri, 19 Aug 2022 12:34:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353365AbiHSQb1 (ORCPT ); Fri, 19 Aug 2022 12:31:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4057811DF66; Fri, 19 Aug 2022 09:05:48 -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 dfw.source.kernel.org (Postfix) with ESMTPS id BB3B7612DF; Fri, 19 Aug 2022 16:05:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB496C433D6; Fri, 19 Aug 2022 16:05:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660925134; bh=Za0Azl4NUkOLxjsN8UNe5yuo9otj5wpPiE41bAZ7fu8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gn+QIO7w+kF97StUGkEmaEcbbqJUKAoYDCCuOE83oFamRlNloMZ/nX5LzkiCQM48C R7DLSM3Y2xOMyVcsnM/n271laQFV/7PzD6sn7Zd4z0Jp3GUZXtpDZzghkL7FPE1+Q3 /CBRfyMMVsTYn/j3RNAebeVmv+R2HK2e0XKz+Wfg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Starke , Sasha Levin Subject: [PATCH 5.10 394/545] tty: n_gsm: fix wrong T1 retry count handling Date: Fri, 19 Aug 2022 17:42:44 +0200 Message-Id: <20220819153847.047153638@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220819153829.135562864@linuxfoundation.org> References: <20220819153829.135562864@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Daniel Starke [ Upstream commit f30e10caa80aa1f35508bc17fc302dbbde9a833c ] 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/SpecificationDeta= ils.aspx?specificationId=3D1516 The changes from 07.010 to 27.010 are non-functional. Therefore, I refer to the newer 27.010 here. Chapter 5.7.3 states that the valid range for the maximum number of retransmissions (N2) is from 0 to 255 (both including). gsm_dlci_t1() handles this number incorrectly by performing N2 - 1 retransmission attempts. Setting N2 to zero results in more than 255 retransmission attempts. Fix gsm_dlci_t1() to comply with 3GPP 27.010. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke Link: https://lore.kernel.org/r/20220707113223.3685-1-daniel.starke@siemens= .com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/n_gsm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 969c0de788f8..3f100f7abdb7 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1550,8 +1550,8 @@ static void gsm_dlci_t1(struct timer_list *t) =20 switch (dlci->state) { case DLCI_OPENING: - dlci->retries--; if (dlci->retries) { + dlci->retries--; gsm_command(dlci->gsm, dlci->addr, SABM|PF); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); } else if (!dlci->addr && gsm->control =3D=3D (DM | PF)) { @@ -1566,8 +1566,8 @@ static void gsm_dlci_t1(struct timer_list *t) =20 break; case DLCI_CLOSING: - dlci->retries--; if (dlci->retries) { + dlci->retries--; gsm_command(dlci->gsm, dlci->addr, DISC|PF); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); } else --=20 2.35.1