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 055B2C47092 for ; Tue, 12 Apr 2022 07:25:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352331AbiDLHXv (ORCPT ); Tue, 12 Apr 2022 03:23:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354060AbiDLHQ4 (ORCPT ); Tue, 12 Apr 2022 03:16:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C019348882; Mon, 11 Apr 2022 23:58:06 -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 0588B615A4; Tue, 12 Apr 2022 06:58:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A942C385A6; Tue, 12 Apr 2022 06:58:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649746685; bh=b/+qkuaKqcpsC6aEEb3D76mekCKpkMRju0VRn4DhoMc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=noOiP1r+jyXdrKoi9DWVBdssEHrq7rYCmfgsowbYZNY9h5wIGSEVkTRO5EJSUUqNv GNxkfyXNr4K+N0zRjf4GnOMr7rodHCK3gmlWWqTvH8wcIlcd40a7+BZQul2XU+tMQv du0kdHDFc+JUwGG21XJXkHSeu+IU70kxn7Uv+q4c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vincent Mailhol , Marc Kleine-Budde , Sasha Levin Subject: [PATCH 5.16 094/285] can: etas_es58x: es58x_fd_rx_event_msg(): initialize rx_event_msg before calling es58x_check_msg_len() Date: Tue, 12 Apr 2022 08:29:11 +0200 Message-Id: <20220412062946.376907108@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062943.670770901@linuxfoundation.org> References: <20220412062943.670770901@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vincent Mailhol [ Upstream commit 7a8cd7c0ee823a1cc893ab3feaa23e4b602bfb9a ] Function es58x_fd_rx_event() invokes the es58x_check_msg_len() macro: | ret = es58x_check_msg_len(es58x_dev->dev, *rx_event_msg, msg_len); While doing so, it dereferences an uninitialized variable: *rx_event_msg. This is actually harmless because es58x_check_msg_len() only uses preprocessor macros (sizeof() and __stringify()) on *rx_event_msg. c.f. [1]. Nonetheless, this pattern is confusing so the lines are reordered to make sure that rx_event_msg is correctly initialized. This patch also fixes a false positive warning reported by cppcheck: | cppcheck possible warnings: (new ones prefixed by >>, may not be real problems) | | In file included from drivers/net/can/usb/etas_es58x/es58x_fd.c: | >> drivers/net/can/usb/etas_es58x/es58x_fd.c:174:8: warning: Uninitialized variable: rx_event_msg [uninitvar] | ret = es58x_check_msg_len(es58x_dev->dev, *rx_event_msg, msg_len); | ^ [1] https://elixir.bootlin.com/linux/v5.16/source/drivers/net/can/usb/etas_es58x/es58x_core.h#L467 Link: https://lore.kernel.org/all/20220306101302.708783-1-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- drivers/net/can/usb/etas_es58x/es58x_fd.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/can/usb/etas_es58x/es58x_fd.c b/drivers/net/can/usb/etas_es58x/es58x_fd.c index 4f0cae29f4d8..b71d1530638b 100644 --- a/drivers/net/can/usb/etas_es58x/es58x_fd.c +++ b/drivers/net/can/usb/etas_es58x/es58x_fd.c @@ -171,12 +171,11 @@ static int es58x_fd_rx_event_msg(struct net_device *netdev, const struct es58x_fd_rx_event_msg *rx_event_msg; int ret; + rx_event_msg = &es58x_fd_urb_cmd->rx_event_msg; ret = es58x_check_msg_len(es58x_dev->dev, *rx_event_msg, msg_len); if (ret) return ret; - rx_event_msg = &es58x_fd_urb_cmd->rx_event_msg; - return es58x_rx_err_msg(netdev, rx_event_msg->error_code, rx_event_msg->event_code, get_unaligned_le64(&rx_event_msg->timestamp)); -- 2.35.1