From patchwork Tue Jun 13 17:20:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 775363 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org 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 3wnGld6m9Bz9s8P for ; Wed, 14 Jun 2017 03:21:49 +1000 (AEST) Received: from localhost ([::1]:44417 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dKpVj-0003FN-Mx for incoming@patchwork.ozlabs.org; Tue, 13 Jun 2017 13:21:47 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57520) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dKpUH-0002cX-MS for qemu-devel@nongnu.org; Tue, 13 Jun 2017 13:20:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dKpUG-00010V-Q4 for qemu-devel@nongnu.org; Tue, 13 Jun 2017 13:20:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53678) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dKpUE-0000yf-5L; Tue, 13 Jun 2017 13:20:14 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0C6257FD46; Tue, 13 Jun 2017 17:20:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 0C6257FD46 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=mreitz@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 0C6257FD46 Received: from localhost (ovpn-204-68.brq.redhat.com [10.40.204.68]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 58744A3955; Tue, 13 Jun 2017 17:20:12 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Tue, 13 Jun 2017 19:20:05 +0200 Message-Id: <20170613172006.19685-2-mreitz@redhat.com> In-Reply-To: <20170613172006.19685-1-mreitz@redhat.com> References: <20170613172006.19685-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 13 Jun 2017 17:20:13 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 1/2] blkdebug: Catch bs->exact_filename overflow 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: , Cc: Kevin Wolf , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The bs->exact_filename field may not be sufficient to store the full blkdebug node filename. In this case, we should not generate a filename at all instead of an unusable one. Cc: qemu-stable@nongnu.org Reported-by: Qu Wenruo Signed-off-by: Max Reitz --- block/blkdebug.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/block/blkdebug.c b/block/blkdebug.c index a5196e8..6166d6a 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -840,9 +840,13 @@ static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *options) } if (!force_json && bs->file->bs->exact_filename[0]) { - snprintf(bs->exact_filename, sizeof(bs->exact_filename), - "blkdebug:%s:%s", s->config_file ?: "", - bs->file->bs->exact_filename); + int ret = snprintf(bs->exact_filename, sizeof(bs->exact_filename), + "blkdebug:%s:%s", s->config_file ?: "", + bs->file->bs->exact_filename); + if (ret >= sizeof(bs->exact_filename)) { + /* An overflow makes the filename unusable, so do not report any */ + bs->exact_filename[0] = 0; + } } opts = qdict_new();