From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7BFCA3D6B for ; Sun, 18 Dec 2022 16:20:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC718C433EF; Sun, 18 Dec 2022 16:20:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671380433; bh=FpBev2TRlBot6nW8kIO6yuMp+zZp19D+9AzteDvmyig=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nDWZAdTdp42D/Df8koVT42kNXPnyVAKM2jQr38cr3ua/aj1AdBChwswOAv15JNrw0 pBbEHwa6eNpigN6wGINQWHIr2NVvXXuKzrb63AUaVu+GNzHsXmbfJRbYPQRXop7DEB k87mYVW9fa0+u9CZ4kvoiNx7TKpHxZ2zOE90HMOyNkDgkchA8Zkhc55650PlXHN8uK DIpFFvYpM77g+2KZcIqzKTtktbsPXzxH7lhSbiwGLDKWCJFQohbDedlTvz1c2StWqO 7+f/iJX7rGRxEnfoV8pLFTsIvnR1sFQv7GttFMuWMV72pd1WhzGFwoQzyutYlREx+/ VxDSY6RT7FoOw== 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, mkl@pengutronix.de, wintera@linux.ibm.com, mathew.j.martineau@linux.intel.com, elder@linaro.org, colin.i.king@gmail.com, netdev@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 4.19 06/26] net: ethernet: ti: Fix return type of netcp_ndo_start_xmit() Date: Sun, 18 Dec 2022 11:19:56 -0500 Message-Id: <20221218162016.934280-6-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218162016.934280-1-sashal@kernel.org> References: <20221218162016.934280-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit 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 6099865217f2..7fdbd2ff5573 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