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 CA48CC00140 for ; Wed, 10 Aug 2022 09:08:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231959AbiHJJIT (ORCPT ); Wed, 10 Aug 2022 05:08:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231906AbiHJJIR (ORCPT ); Wed, 10 Aug 2022 05:08:17 -0400 Received: from EUR04-DB3-obe.outbound.protection.outlook.com (mail-eopbgr60054.outbound.protection.outlook.com [40.107.6.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2CE5676479 for ; Wed, 10 Aug 2022 02:08:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=m+n9TwbkWgWDUa/IUKOAjtZoGr4C2XJskHqKj0VU61dEok/XS+J5I+LJ51dxkC6HBaCkeGi71cZoepOPI6X5cPv5YPjvdgIMgcgrj/L3b991KbuBFgPxSO3zbajZeM28Rp8JNlLbW5Jc9/mTz20TMZcG/KyTymxkJ2AgFt6xoV7+GMDnBvhhp1swggyLoBfzuxlVvBS4qNNSicw0/Y5xtOt/uqt/2IGe92J1r0SrL17Msuo2v7E6L1D27BHPbWL1GevuBmibt2Euj6BnunGQBhiewd5YtwwIUjSpUUNsfzDXmlvJdaF8QmW1ftwGmOCSxDPmPCA4IEIMsucj69Vf7A== ARC-Message-Signature: i=1; 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charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: siemens.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: DB9PR10MB5881.EURPRD10.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-Network-Message-Id: 659118d2-5c1e-4b8d-c5cb-08da7aafdaf3 X-MS-Exchange-CrossTenant-originalarrivaltime: 10 Aug 2022 09:08:13.7308 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 38ae3bcd-9579-4fd4-adda-b42e1495d55a X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: b6C2SzKl1/6THBdLKpcnSTcGTTc7YQ6iCFe8RJZRoYz6sACb7xg/E0i0b9wZ/Wb02njUem58OSO+87yaWHRiMRgq4kEDfMUbQzRKQwD/WZ8= X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM8PR10MB4644 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Fix this by setting the gsm->receive() function when the line=20 > discipline is being attached to the terminal device, inside=20 > gsmld_attach_gsm(). This will guarantee that the function is assigned=20 > and a call to TIOCSTI, which calls gsmld_receive_buf(), will not > reference a null pointer. In my opinion there are only two possible ways to fix this: a) Move the gsm->receive initialization from gsm_activate_mux() to gsmld_attach_gsm(). b) Avoid calling gsm->receive in gsmld_receive_buf() if not initialized. The current code might assume that gsm->receive is only called after MUX activation. Therefore, variant a) may break the code in other places. I see no need to initialize gsm->receive in gsm_activate_mux() and gsmld_attach_gsm(). Best regards, Daniel Starke 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 smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F1D67C25B08 for ; Wed, 10 Aug 2022 09:08:20 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 68A5140193; Wed, 10 Aug 2022 09:08:20 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 68A5140193 Authentication-Results: smtp4.osuosl.org; dkim=fail reason="signature verification failed" (2048-bit key, unprotected) header.d=siemens.com header.i=@siemens.com header.a=rsa-sha256 header.s=selector2 header.b=ROpV6S68 X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ECKh0uuvtrZE; 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charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" > Fix this by setting the gsm->receive() function when the line > discipline is being attached to the terminal device, inside > gsmld_attach_gsm(). This will guarantee that the function is assigned > and a call to TIOCSTI, which calls gsmld_receive_buf(), will not > reference a null pointer. In my opinion there are only two possible ways to fix this: a) Move the gsm->receive initialization from gsm_activate_mux() to gsmld_attach_gsm(). b) Avoid calling gsm->receive in gsmld_receive_buf() if not initialized. The current code might assume that gsm->receive is only called after MUX activation. Therefore, variant a) may break the code in other places. I see no need to initialize gsm->receive in gsm_activate_mux() and gsmld_attach_gsm(). Best regards, Daniel Starke _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees