From patchwork Tue Aug 21 16:47:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Williamson X-Patchwork-Id: 960559 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 41vxXD6JjRz9s4v for ; Wed, 22 Aug 2018 02:51:24 +1000 (AEST) Received: from localhost ([::1]:54840 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fs9sI-00074z-Ew for incoming@patchwork.ozlabs.org; Tue, 21 Aug 2018 12:51:22 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51878) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fs9pI-00041y-R6 for qemu-devel@nongnu.org; Tue, 21 Aug 2018 12:48:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fs9od-0007Wp-B2 for qemu-devel@nongnu.org; Tue, 21 Aug 2018 12:47:39 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42648 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fs9oX-00079j-Vu for qemu-devel@nongnu.org; Tue, 21 Aug 2018 12:47:31 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 87C117DAC9 for ; Tue, 21 Aug 2018 16:47:28 +0000 (UTC) Received: from gimli.home (ovpn-120-10.rdu2.redhat.com [10.10.120.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4E1A31010400; Tue, 21 Aug 2018 16:47:26 +0000 (UTC) From: Alex Williamson To: qemu-devel@nongnu.org Date: Tue, 21 Aug 2018 10:47:26 -0600 Message-ID: <153487003791.14686.6509954487216084042.stgit@gimli.home> In-Reply-To: <153486991405.14686.16930315204565109405.stgit@gimli.home> References: <153486991405.14686.16930315204565109405.stgit@gimli.home> User-Agent: StGit/0.18-136-gffd7-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Tue, 21 Aug 2018 16:47:28 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Tue, 21 Aug 2018 16:47:28 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'alex.williamson@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PULL 1/1] vfio/pci: Handle subsystem realpath() returning NULL X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Fix error reported by Coverity where realpath can return NULL, resulting in a segfault in strcmp(). This should never happen given that we're working through regularly structured sysfs paths, but trivial enough to easily avoid. Fixes: 238e91728503 ("vfio/ccw/pci: Allow devices to opt-in for ballooning") Signed-off-by: Alex Williamson --- hw/vfio/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 056f3a887a8f..866f0deeb7eb 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -2879,7 +2879,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp) tmp = g_strdup_printf("%s/subsystem", vdev->vbasedev.sysfsdev); subsys = realpath(tmp, NULL); g_free(tmp); - is_mdev = (strcmp(subsys, "/sys/bus/mdev") == 0); + is_mdev = subsys && (strcmp(subsys, "/sys/bus/mdev") == 0); free(subsys); trace_vfio_mdev(vdev->vbasedev.name, is_mdev);