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 1EDE21875 for ; Wed, 28 Dec 2022 15:52:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 977DFC433D2; Wed, 28 Dec 2022 15:52:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672242744; bh=74oED/ABmW0A+X9spJM7GV1K+ZhLhsueqGtIF4eopHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y6XtaMQK6nwZ1uaWzKBQDujupAg14z8ljTlLOjf6QQmeaX4zAg1mIfqZaDUdBtT4O qLpL0LKTZJ7XCmoe6CZMaxDHagU0SX8sg7qaTBgvmZ4LsUI/TNgM6oi2dV8fYMXIqv 3rRx00YUIfVg7ISkDAzCDRKzoC4s6vCfFmO2XbJY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nathan Chancellor , Kees Cook , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 640/731] net: ethernet: ti: Fix return type of netcp_ndo_start_xmit() Date: Wed, 28 Dec 2022 15:42:27 +0100 Message-Id: <20221228144315.061092826@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144256.536395940@linuxfoundation.org> References: <20221228144256.536395940@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 eda2961c0fe2..07bdeece1723 100644 --- a/drivers/net/ethernet/ti/netcp_core.c +++ b/drivers/net/ethernet/ti/netcp_core.c @@ -1262,7 +1262,7 @@ 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