From mboxrd@z Thu Jan 1 00:00:00 1970 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) From: Alex Williamson 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> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PULL 1/1] vfio/pci: Handle subsystem realpath() returning NULL List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org 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);