From patchwork Wed May 4 16:45:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 569813 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 79D9EC433FE for ; Wed, 4 May 2022 17:02:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355030AbiEDRFf (ORCPT ); Wed, 4 May 2022 13:05:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354998AbiEDRDs (ORCPT ); Wed, 4 May 2022 13:03:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB7734D9E8; Wed, 4 May 2022 09:52:38 -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 8150961794; Wed, 4 May 2022 16:52:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBA75C385AA; Wed, 4 May 2022 16:52:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651683139; bh=Y0Bi39iTWz4cj+MRckiLDH8gQu2Z0CGTg8tiDnDMg9A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DER4vhqKCqLjyjXHvOlC/b9x5qRYPIbjTH3xQhethf7F/+M2zHHp1fB8SsrGC8zdS kxmsRjZcFjln8CyyXVrEFee4v2yaDFwNFduD5B6T34t/446dTAwUSbpgP8qsGJ+c42 2jutqw+T2w5KW9dPxBbp8wTDxnhxD6iu9o8AFe68= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Starke Subject: [PATCH 5.10 127/129] tty: n_gsm: fix incorrect UA handling Date: Wed, 4 May 2022 18:45:19 +0200 Message-Id: <20220504153031.655306116@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220504153021.299025455@linuxfoundation.org> References: <20220504153021.299025455@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 @@ -1817,7 +1817,6 @@ 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;