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 71AA9C4332F for ; Sun, 18 Dec 2022 17:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233363AbiLRRGn (ORCPT ); Sun, 18 Dec 2022 12:06:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233374AbiLRRFe (ORCPT ); Sun, 18 Dec 2022 12:05:34 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AEB0112D08; Sun, 18 Dec 2022 08:22:09 -0800 (PST) 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 64946B801C0; Sun, 18 Dec 2022 16:22:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0911C433D2; Sun, 18 Dec 2022 16:22:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380527; bh=4OcEmr7LNw5JhWwNkW0lssKkXyeGSeMB4pbfvhi0gV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p5RVt/C27y7txeMsJc5XT/lbtYRePBqHiZ5PhGzC8x1rEzqcak39g142h1BRPIykY wg8AU8kmjNOn/2ALqMAJDjzGItS6mnlVn9jEd/k7CU9pUyRAfGH8W2bCeCxY2S3Qiy ZE2VArTZvfGpL5DXEQPts+ihlOrqGccj5ReHAHLhdaLvbo11BLFc5SgXBhiU+EmP/1 2u/50/BbScHdNxuWpizDa50hNl3YhRIKh+DaG566Zr8MDmVertpNacql+w7R2Rs5bq WPrI1liQrDi6DoWgPrxuGOsVsL8BPGWrYjAnjKUxhGwFTN4VXhW+TbjCaWUkvwhRr+ Y+/PSmWCrvZNQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Chancellor , Kees Cook , Jakub Kicinski , Sasha Levin , davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, ndesaulniers@google.com, colin.i.king@gmail.com, paul@xen.org, elder@linaro.org, netdev@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 4.14 06/23] net: ethernet: ti: Fix return type of netcp_ndo_start_xmit() Date: Sun, 18 Dec 2022 11:21:32 -0500 Message-Id: <20221218162149.935047-6-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218162149.935047-1-sashal@kernel.org> References: <20221218162149.935047-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Nathan Chancellor [ Upstream commit 63fe6ff674a96cfcfc0fa8df1051a27aa31c70b4 ] 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/net/ethernet/ti/netcp_core.c:1944:21: 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 = netcp_ndo_start_xmit, ^~~~~~~~~~~~~~~~~~~~ 1 error generated. ->ndo_start_xmit() in 'struct net_device_ops' expects a return type of 'netdev_tx_t', not 'int'. Adjust the return type of netcp_ndo_start_xmit() to match the prototype's to resolve the warning and CFI failure. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Signed-off-by: Nathan Chancellor Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20221102160933.1601260-1-nathan@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/ti/netcp_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/ti/netcp_core.c b/drivers/net/ethernet/ti/netcp_core.c index 452cf6cfd179..90770a2755b6 100644 --- a/drivers/net/ethernet/ti/netcp_core.c +++ b/drivers/net/ethernet/ti/netcp_core.c @@ -1276,7 +1276,7 @@ static int netcp_tx_submit_skb(struct netcp_intf *netcp, } /* Submit the packet */ -static int netcp_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev) +static netdev_tx_t netcp_ndo_start_xmit(struct sk_buff *skb, struct net_device *ndev) { struct netcp_intf *netcp = netdev_priv(ndev); struct netcp_stats *tx_stats = &netcp->stats; -- 2.35.1