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 780CAC3DA7C for ; Sun, 18 Dec 2022 16:06:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231438AbiLRQG0 (ORCPT ); Sun, 18 Dec 2022 11:06:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231267AbiLRQEz (ORCPT ); Sun, 18 Dec 2022 11:04:55 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01A76B1F5; Sun, 18 Dec 2022 08:03:21 -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 B834AB80BA5; Sun, 18 Dec 2022 16:03:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18DE2C43396; Sun, 18 Dec 2022 16:03:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671379398; bh=jlpB92qp8qPbGD3eBHDDa59gnNq7MLHT6unlOv+GfzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JD4IL4UoW/aHYGuKDTeAEFs9RR4XSqm6QiPYrnh6p+w05fS3gvpKY9O2aUtJNsDLs 6I4cc2/LOFSDIutqlNmSs11D8M2FcyUmmwG+e2w/HyEouEK8trYi9sg2m1DsASGP1o P9qw5e4GoUKtB/I1924ZehOrtzi2WWX7Tn7W99+GSEmSIVlb0r4y34rbj3JMXx+JOD 74ufoswaSMOJr1enHqQcuwTqYaoVJEqMXitvcyRqUJvdlH51Z2tC9lPzio6oLKM5aN 7GxereImUb1+/5iYMQd1WqL96+P/O9DkSJkDUo0+7rLzIUdr18RNdIj1PDX5O5KlUB 0EjXYSWwKkcEw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Chancellor , Kees Cook , Jakub Kicinski , Sasha Levin , t.sailer@alumni.ethz.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, ndesaulniers@google.com, linux-hams@vger.kernel.org, netdev@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 6.1 25/85] hamradio: baycom_epp: Fix return type of baycom_send_packet() Date: Sun, 18 Dec 2022 11:00:42 -0500 Message-Id: <20221218160142.925394-25-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218160142.925394-1-sashal@kernel.org> References: <20221218160142.925394-1-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 c5733e5b15d91ab679646ec3149e192996a27d5d ] 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/hamradio/baycom_epp.c:1119:25: 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 = baycom_send_packet, ^~~~~~~~~~~~~~~~~~ 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 baycom_send_packet() 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/20221102160610.1186145-1-nathan@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/hamradio/baycom_epp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/hamradio/baycom_epp.c b/drivers/net/hamradio/baycom_epp.c index 791b4a53d69f..bd3b0c2655a2 100644 --- a/drivers/net/hamradio/baycom_epp.c +++ b/drivers/net/hamradio/baycom_epp.c @@ -758,7 +758,7 @@ static void epp_bh(struct work_struct *work) * ===================== network driver interface ========================= */ -static int baycom_send_packet(struct sk_buff *skb, struct net_device *dev) +static netdev_tx_t baycom_send_packet(struct sk_buff *skb, struct net_device *dev) { struct baycom_state *bc = netdev_priv(dev); -- 2.35.1