From patchwork Wed Nov 2 16:32:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 14385 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp16295wru; Wed, 2 Nov 2022 09:40:40 -0700 (PDT) X-Google-Smtp-Source: AMsMyM41QsDUUax14aVtUcAwNyFNr6OpawCzf2b4uq9/lfIoWafYaIDsGTUhCm61PlScRZ0JtuBk X-Received: by 2002:a17:902:aa44:b0:186:7a6b:7bbd with SMTP id c4-20020a170902aa4400b001867a6b7bbdmr26015463plr.78.1667407239800; Wed, 02 Nov 2022 09:40:39 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667407239; cv=none; d=google.com; s=arc-20160816; b=r1um7lMZPrkQBDMlqMZIYJTGEQ+NoNpPziV1aTyjyk3yNyikoSQ7zfndygbFDjsBeA mAqHpApeebtw43a3uwlaQV3ZljLvLHdgCtGs2rW2hAwj5QPc7S6Pwl4zaxNY+rjCvx+L Bv3UHy5D9Kz9k9aLgZyVox7SJ/G1b3SoOxcNPKocR3tS/UvNW8ne3I2mo76w8s56O8f3 tbRidt47ExS65sUKxg7LlTJfQ5VhmnFm6UOB48kQrJysTJmvyggMCclDHhvwYM2g4sGv +3dPNRoZIg8JUVEOqxyRXtEAQ0UhlbxnVr7tUpl0z4pBya+yJXkCPzobOIYMdcE0sJK/ vLlg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=4ZhT+KdADqCdYCqodP2ce9CLKP+XZ8yjs4grfZ5s1Zw=; b=qWn/XiGwFv8eLf/PrLvunYTB2WBzfFvqyvvCOxcyAbo62bnZYQiNXq2BM0qiGkLJy4 gBE9cPJ7CrQkzccUwuyR4yWQjsiwGuW+n9jwvG/R0l2aSBIEoYmL/BsLp8hbkKAENTB6 4ooOx4W6FJz/f02uWVAC79+2KUqwPCrGGGuEYtfa31SnaLktNeXSrKtaZgXOv7znnYPe fOyVzXxxDP7O+04PWPlb/7M3U/a4zkl8b7oVFXn/xZfZYvJSImlaTsk+f/TPCWyFCI9l VNi4HsfvfSUisg/OKtLzP2KbOTq0XKmCOy/OgvTBaS4wlaNdpn9kSTpXLEtvAXMG/vAh HsIw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=OVWh4pJE; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id f6-20020a170902ce8600b00186ffe624e8si20810382plg.436.2022.11.02.09.40.14; Wed, 02 Nov 2022 09:40:39 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=OVWh4pJE; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231803AbiKBQiV (ORCPT + 99 others); Wed, 2 Nov 2022 12:38:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231721AbiKBQh4 (ORCPT ); Wed, 2 Nov 2022 12:37:56 -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 9F0C431DE1; Wed, 2 Nov 2022 09:33:01 -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 EDA8761A56; Wed, 2 Nov 2022 16:33:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C573C433C1; Wed, 2 Nov 2022 16:32:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667406780; bh=X6xqT5Q+gVJ0fSUPZGCRiXKotwL6OxS8B+0WmVkabE4=; h=From:To:Cc:Subject:Date:From; b=OVWh4pJER+b69tT/lzefyIZrWEZ5hg0SPIMfoJWLTsR9bJbMocFw4sqplf61P4ZTG o0V14tacLjtPAz4u8ic5H5OYNRr6xxm9P20i1jPDXC+ksocQi2J3QBCWd4sDxKgBg0 VSJdSVkI3PdRgsbebmf06LtHYSYZp5+9xrZZv9Jzyp3gl9erOAQeAWCQmZlSBsqREX /8nR88FXpSezKRBWnpTKSweTw9QSu8EbYBP2a8ECv/uS6eBr74jBY+kk0ttipIKWWH QJU/7XSrni5lMQ0YbkB2WKjJqEEBbkX+xnETcMD/8JXHgKGEXUt0OhU0rYuTyMPWy5 308C7CV67PCgA== From: Nathan Chancellor To: Alexandra Winter , Wenjia Zhang Cc: Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org, netdev@vger.kernel.org, Nick Desaulniers , Tom Rix , Kees Cook , Sami Tolvanen , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Nathan Chancellor Subject: [PATCH 1/3] s390/ctcm: Fix return type of ctc{mp,}m_tx() Date: Wed, 2 Nov 2022 09:32:50 -0700 Message-Id: <20221102163252.49175-1-nathan@kernel.org> X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 X-Spam-Status: No, score=-8.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748403214258154140?= X-GMAIL-MSGID: =?utf-8?q?1748403214258154140?= With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/s390/net/ctcm_main.c:1064:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = ctcm_tx, ^~~~~~~ drivers/s390/net/ctcm_main.c:1072:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = ctcmpc_tx, ^~~~~~~~~ ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of ctc{mp,}m_tx() to match the prototype's to resolve the warning and potential CFI failure, should s390 select ARCH_SUPPORTS_CFI_CLANG in the future. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Signed-off-by: Nathan Chancellor Reviewed-by: Kees Cook Reviewed-by: Alexandra Winter --- drivers/s390/net/ctcm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) base-commit: 9abf2313adc1ca1b6180c508c25f22f9395cc780 diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c index 37b551bd43bf..4eea7d0285c1 100644 --- a/drivers/s390/net/ctcm_main.c +++ b/drivers/s390/net/ctcm_main.c @@ -834,7 +834,7 @@ static int ctcmpc_transmit_skb(struct channel *ch, struct sk_buff *skb) * the generic network layer. */ /* first merge version - leaving both functions separated */ -static int ctcm_tx(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t ctcm_tx(struct sk_buff *skb, struct net_device *dev) { struct ctcm_priv *priv = dev->ml_priv; @@ -877,7 +877,7 @@ static int ctcm_tx(struct sk_buff *skb, struct net_device *dev) } /* unmerged MPC variant of ctcm_tx */ -static int ctcmpc_tx(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t ctcmpc_tx(struct sk_buff *skb, struct net_device *dev) { int len = 0; struct ctcm_priv *priv = dev->ml_priv; From patchwork Wed Nov 2 16:32:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 14383 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp15955wru; Wed, 2 Nov 2022 09:39:41 -0700 (PDT) X-Google-Smtp-Source: AMsMyM5fclwPLXEo4PdqNMhUW8EBUz+ZplHG8RI4y176FWn8+smUNcJRon6CWpghml1dJn8BYwy6 X-Received: by 2002:aa7:d590:0:b0:463:d21a:f0af with SMTP id r16-20020aa7d590000000b00463d21af0afmr6843563edq.50.1667407181355; Wed, 02 Nov 2022 09:39:41 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667407181; cv=none; d=google.com; s=arc-20160816; b=hy8t09xFC7D1ekyLTVOTksb0GV78zqf3jmCEBYXxJJyPbOdQmVsBXX2UQ6iLrQnb1f psiaGwMA9i0NXUffTaEGTEwzG+o0iMdVLNYz923JrGMLI+hu5CPCYsZo1vFcqhJSW4Xw RhGJxi7l1UrP4Z+zl1lvVjw/vVb8piqGP85Oq+KNkignFeVynhF2n+geUfY/TQ3Sd4Fp EjSXj/ky7sWNi9ciXZSI2r1qfSfOSfqc3Y92Bt4eAzvmUJqe3mUqrUcBlv79HGLVF/U3 PdnVMya7EjPbzwnT23ZZlLpFqms0KRlqhMe6J2dylUfqP+2EiUuPBTPpGgYE4Qep8bkY 5qqg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=19C2yCSa144AGO4+opKrK2/dLvjop1XgG03ic+kwsp0=; b=yuQ4EP6g4uDyyOx0lz/5kfrYDeVSfnK/xSsxO8CLksbprdhcpxvzzGIY/qx8qhvcT/ 4DYtNZzR5GO7ReprXOHtgGYT+NMqhoi4nqpNH2dMGvhyyq19Nc+aGnCK8lvE4hJPaXP3 XeBYW4z2qUX7hxr72+umhtv+/1g5qGYswoeRj6+J+mxgnIB0mXLUqSFSDeEAiHQJ6Cf7 C0mNrrvozZ+XSp3w4nw9d6dz9PhSYN2WcD5Gi4BD8PNzv5oikXj4aB1GfuMuVFxKmmsx 3YRyNVNeEBFH41oumpO1lfIwqOnVY4o/cyrfFPzH476rPE+tS/drVeUPFahIyjQfL9zB FRRQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=nSttuC6K; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id dr19-20020a170907721300b0079b8cce1170si15869002ejc.950.2022.11.02.09.39.17; Wed, 02 Nov 2022 09:39:41 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=nSttuC6K; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231925AbiKBQjE (ORCPT + 99 others); Wed, 2 Nov 2022 12:39:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231171AbiKBQi2 (ORCPT ); Wed, 2 Nov 2022 12:38:28 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BED5A12754; Wed, 2 Nov 2022 09:33:28 -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 46DD9B821A5; Wed, 2 Nov 2022 16:33:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FB74C433D7; Wed, 2 Nov 2022 16:33:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667406788; bh=50kQ6owO8SzQI6+G9QUfCAtJgqi3aZcY8S6jn9Ofr0o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nSttuC6KSjo+IQVF76/jjjClrLvoQHgT+PX1bOq4XwGjMOLako3E74Y2OSytwTTSu ki4QDY5vd5dJrtfQDQPSIhhWAiGQNkcD6HE6ND65niRNelLkNP7x9ejmzInvlf7yuK OJCqp50qW8GUhayJIm6OAbrED/7R22a82WaEjwNrEhmwvj/spvEe6bVe/9zkBevvuW EH2BoR05PAMP263XSTMGAeJFooshLEJC1ZyVPkigcT36bJf2hnGoxGWlmSRR3ktzwo 9ZQyyrQO9HSVANaqo/8UFuYBEG/hCgrF9siFoiGiYftf8WBSNOCuQaESpTWtJqoY9A YHdQhDqyGiCnQ== From: Nathan Chancellor To: Alexandra Winter , Wenjia Zhang Cc: Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org, netdev@vger.kernel.org, Nick Desaulniers , Tom Rix , Kees Cook , Sami Tolvanen , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Nathan Chancellor Subject: [PATCH 2/3] s390/netiucv: Fix return type of netiucv_tx() Date: Wed, 2 Nov 2022 09:32:51 -0700 Message-Id: <20221102163252.49175-2-nathan@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221102163252.49175-1-nathan@kernel.org> References: <20221102163252.49175-1-nathan@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-8.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748403152703323198?= X-GMAIL-MSGID: =?utf-8?q?1748403152703323198?= With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/s390/net/netiucv.c:1854:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = netiucv_tx, ^~~~~~~~~~ ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of netiucv_tx() to match the prototype's to resolve the warning and potential CFI failure, should s390 select ARCH_SUPPORTS_CFI_CLANG in the future. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Signed-off-by: Nathan Chancellor Reviewed-by: Kees Cook Reviewed-by: Alexandra Winter --- drivers/s390/net/netiucv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/s390/net/netiucv.c b/drivers/s390/net/netiucv.c index 65aa0a96c21d..1a7f2bc3a87b 100644 --- a/drivers/s390/net/netiucv.c +++ b/drivers/s390/net/netiucv.c @@ -1256,7 +1256,7 @@ static int netiucv_close(struct net_device *dev) * Note: If we return !0, then the packet is free'd by * the generic network layer. */ -static int netiucv_tx(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t netiucv_tx(struct sk_buff *skb, struct net_device *dev) { struct netiucv_priv *privptr = netdev_priv(dev); int rc; From patchwork Wed Nov 2 16:32:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 14382 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp15774wru; Wed, 2 Nov 2022 09:39:08 -0700 (PDT) X-Google-Smtp-Source: AMsMyM6TyaryuKYN6eApxHQSmQnJGCL5wpw+TNpOOOCMqFvFo7iH9f8OsukcmOXNIevGFETOO/R/ X-Received: by 2002:a05:6402:5c9:b0:446:fb0:56bb with SMTP id n9-20020a05640205c900b004460fb056bbmr26111172edx.173.1667407148498; Wed, 02 Nov 2022 09:39:08 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667407148; cv=none; d=google.com; s=arc-20160816; b=N+Hp2v2D9XLLXF9TIG0vXDklYMzQ6AePNmm1G9l1IJcwDtzshC4Kl3mCsVw9apW8Wh /tJzz+iNV9aJNEXSsHRR/zkl+HIKzcrB/R9ozfv0bMT7r6Q40JF897ET9sNbINLjnkfF orJwZQ1infX2wJT6Gsbi9GfQtA/ylx6+JuXWQ+wf6F3GHBBrZtOXilKP4QdT3aC9wY+E 0HqfNzlO+EA1yAIukg5x/CMmx5a+Mb/KJ4Zov9gpJgVdqYwNJvW6/H5piaIrbVMlDm3u DoEiCf1XA0MOAsThEaPllHVAUTZ636AuvY/hU/fkf4Pbwn0XJfbZt0d2RLTVyz1LuWY3 FO3Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=3m+oE0Q7ZaiYN9hYqempjLRCSoMHfNw4QqDmebuOhmc=; b=USvGWdaL2P9wzwRh0nZfYcjhziFb/QT64bQ2rojc0bsB7JV/UeJsFFYR6T9i6PEpCj M9vHE7prgSe8ap/hNZqPJ7nqL3ULmrjeeK2yr3uum82jba9RxQ7iCv3sFXrHbp+exvrw CQot8keB+6fRd4fNLLiQev0A5KT25pngUC0eGeE8T4pwVbm1iWdU8weFCDerAHd7U4U9 fxtHlXgrXU4YBrPN/bfzkpbPHdodDESRDLsdaVkZhF0w2vEDYCq53YXsW7YZiG+jzKcm XiYVEbphXrBxIDXhY192cu9cPAxTXxDkGGMdF/z/grmbpABdo/mWnY33SfJil7I4U/Pm mp9Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=YkVMEabL; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id f20-20020a0564021e9400b004637e16cf97si11956925edf.597.2022.11.02.09.38.43; Wed, 02 Nov 2022 09:39:08 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=YkVMEabL; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231495AbiKBQig (ORCPT + 99 others); Wed, 2 Nov 2022 12:38:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231408AbiKBQiK (ORCPT ); Wed, 2 Nov 2022 12:38:10 -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 2860A31ECC; Wed, 2 Nov 2022 09:33:13 -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 E7F9EB821A3; Wed, 2 Nov 2022 16:33:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ADFACC433D6; Wed, 2 Nov 2022 16:33:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667406789; bh=ZaNRk9XsK/SEJ/1Ji5JmKKMuERlYmmNZ5RDlsKv/yN8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YkVMEabLh2tHVOFpCHakFtCLP59LlHSUfhdMWu4i1Q1oy/ymN30vFMERBTMkgdtTp ymq2lbFxZGBSxqGhAKdJ2eIb4EQmAYcd2YP66adzMbb7iCa7xd3wZjEnRTetrxt732 1gxaC0PL4fvKZG0KVkxYTKo37/SVTYmmtxQG7DgvSBddVORZ/ccgUDj+RlitrmfmAo Yly3QDywW6xb+a1xY8w3fAhNkO4EwxTL/FQRrz0rQ6Cc0Z0ZP3fpn926O/J6pn/hl3 n8M/jPLP8WOu/JqkrFOqqhX49MQiUi7MZHrGzLzVb74m6Uo+LNodiPWEj0a3ZitXaH 0MvTDIz3zA8rA== From: Nathan Chancellor To: Alexandra Winter , Wenjia Zhang Cc: Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org, netdev@vger.kernel.org, Nick Desaulniers , Tom Rix , Kees Cook , Sami Tolvanen , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, patches@lists.linux.dev, Nathan Chancellor Subject: [PATCH 3/3] s390/lcs: Fix return type of lcs_start_xmit() Date: Wed, 2 Nov 2022 09:32:52 -0700 Message-Id: <20221102163252.49175-3-nathan@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221102163252.49175-1-nathan@kernel.org> References: <20221102163252.49175-1-nathan@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-8.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748403117818201020?= X-GMAIL-MSGID: =?utf-8?q?1748403117818201020?= With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/s390/net/lcs.c:2090:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = lcs_start_xmit, ^~~~~~~~~~~~~~ drivers/s390/net/lcs.c:2097:21: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict] .ndo_start_xmit = lcs_start_xmit, ^~~~~~~~~~~~~~ ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of lcs_start_xmit() to match the prototype's to resolve the warning and potential CFI failure, should s390 select ARCH_SUPPORTS_CFI_CLANG in the future. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Signed-off-by: Nathan Chancellor Reviewed-by: Kees Cook Reviewed-by: Alexandra Winter --- drivers/s390/net/lcs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/s390/net/lcs.c b/drivers/s390/net/lcs.c index 84c8981317b4..4cbb9802bf22 100644 --- a/drivers/s390/net/lcs.c +++ b/drivers/s390/net/lcs.c @@ -1519,7 +1519,7 @@ lcs_txbuffer_cb(struct lcs_channel *channel, struct lcs_buffer *buffer) /* * Packet transmit function called by network stack */ -static int +static netdev_tx_t __lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, struct net_device *dev) { @@ -1582,7 +1582,7 @@ __lcs_start_xmit(struct lcs_card *card, struct sk_buff *skb, return rc; } -static int +static netdev_tx_t lcs_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct lcs_card *card;