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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 17983C5478C for ; Fri, 23 Feb 2024 08:45:41 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rdRA8-0003pM-CV; Fri, 23 Feb 2024 03:44:08 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rdRA0-0003la-KT; Fri, 23 Feb 2024 03:44:02 -0500 Received: from mgamail.intel.com ([192.198.163.7]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rdR9x-0000Bk-Of; Fri, 23 Feb 2024 03:43:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1708677838; x=1740213838; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=6V97dsmp4JAIBUgFfbzez7o/O5Yd5Mg3yF5DrdVp9Q8=; b=LYrd125rsjKyo0dRsUoemLhJvyaK3IWVEPDBc2rHoGT41XIGRwguXNGk Taw62Er00YbS6vD9IjBJkScFRxptQS2lyZPjq0V8mVEi9gX9fRsT9Kn/J O2XVmx4CaULHmjncOxu2g8MlFDP1leLcloei0xe5PNpf0ZCKzCVjJha6I +3puC3k2ls1oRCMqBgqaRn9150dAh2BfgXwP9WlAi3sv85WkMS4pV6//8 fLtQEYkyyZya/yPSWrrI6JAUJ8a0SMnmpHuJr4N918ysvwqmWeNQRrwQy CFht5ncR+2bQNw1n65xlJjhCxt05gcbeNeeq2MASiG68HWcnEYNfzNabn A==; X-IronPort-AV: E=McAfee;i="6600,9927,10992"; a="28413893" X-IronPort-AV: E=Sophos;i="6.06,179,1705392000"; d="scan'208";a="28413893" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2024 00:43:48 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,179,1705392000"; d="scan'208";a="5731867" Received: from liuzhao-optiplex-7080.sh.intel.com ([10.239.160.36]) by fmviesa007.fm.intel.com with ESMTP; 23 Feb 2024 00:43:44 -0800 From: Zhao Liu To: Jonathan Cameron , Fan Ni , Laurent Vivier , Alistair Francis , "Edgar E . Iglesias" , Peter Maydell , "Michael S . Tsirkin" , Marcel Apfelbaum , Alex Williamson , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Markus Armbruster , Paolo Bonzini , Michael Tokarev Cc: qemu-devel@nongnu.org, qemu-arm@nongnu.org, qemu-trivial@nongnu.org, Zhao Liu Subject: [PATCH v2 6/7] hw/vfio/iommufd: Fix missing ERRP_GUARD() in iommufd_cdev_getfd() Date: Fri, 23 Feb 2024 16:56:52 +0800 Message-Id: <20240223085653.1255438-7-zhao1.liu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240223085653.1255438-1-zhao1.liu@linux.intel.com> References: <20240223085653.1255438-1-zhao1.liu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: none client-ip=192.198.163.7; envelope-from=zhao1.liu@linux.intel.com; helo=mgamail.intel.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.002, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Zhao Liu As the comment in qapi/error, dereferencing @errp requires ERRP_GUARD(): * = Why, when and how to use ERRP_GUARD() = * * Without ERRP_GUARD(), use of the @errp parameter is restricted: * - It must not be dereferenced, because it may be null. ... * ERRP_GUARD() lifts these restrictions. * * To use ERRP_GUARD(), add it right at the beginning of the function. * @errp can then be used without worrying about the argument being * NULL or &error_fatal. * * Using it when it's not needed is safe, but please avoid cluttering * the source with useless code. But in iommufd_cdev_getfd(), @errp is dereferenced without ERRP_GUARD(): if (*errp) { error_prepend(errp, VFIO_MSG_PREFIX, path); } Currently, since vfio_attach_device() - the caller of iommufd_cdev_getfd() - is always called in DeviceClass.realize() context and doesn't get the NULL @errp parameter, iommufd_cdev_getfd() hasn't triggered the bug that dereferencing the NULL @errp. To follow the requirement of @errp, add missing ERRP_GUARD() in iommufd_cdev_getfd(). Suggested-by: Markus Armbruster Signed-off-by: Zhao Liu Reviewed-by: Markus Armbruster --- Suggested by credit: Markus: Referred his explanation about ERRP_GUARD(). --- v2: * Add the @errp dereference code in commit message to make review easier. (Markus) --- hw/vfio/iommufd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c index 9bfddc136089..7baf49e6ee9e 100644 --- a/hw/vfio/iommufd.c +++ b/hw/vfio/iommufd.c @@ -116,6 +116,7 @@ static void iommufd_cdev_unbind_and_disconnect(VFIODevice *vbasedev) static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp) { + ERRP_GUARD(); long int ret = -ENOTTY; char *path, *vfio_dev_path = NULL, *vfio_path = NULL; DIR *dir = NULL; -- 2.34.1