From patchwork Wed Aug 6 20:38:57 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 377595 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 BC40C14007B for ; Thu, 7 Aug 2014 07:14:18 +1000 (EST) Received: from localhost ([::1]:41289 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XF8XI-0000yp-Su for incoming@patchwork.ozlabs.org; Wed, 06 Aug 2014 17:14:16 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38005) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XF82w-0008A6-6T for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:43:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XF82m-0005Eo-Av for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:42:54 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:39513) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XF82m-0005Ea-5w for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:42:44 -0400 Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 6 Aug 2014 16:42:42 -0400 Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id 860ACC9002E; Wed, 6 Aug 2014 16:42:34 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by b01cxnp23034.gho.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s76KgfI661538332; Wed, 6 Aug 2014 20:42:41 GMT Received: from d01av01.pok.ibm.com (localhost [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s76KgfbL023003; Wed, 6 Aug 2014 16:42:41 -0400 Received: from localhost ([9.80.101.111]) by d01av01.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id s76Kgf0L022982; Wed, 6 Aug 2014 16:42:41 -0400 From: Michael Roth To: qemu-devel@nongnu.org Date: Wed, 6 Aug 2014 15:38:57 -0500 Message-Id: <1407357598-21541-48-git-send-email-mdroth@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1407357598-21541-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1407357598-21541-1-git-send-email-mdroth@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14080620-7182-0000-0000-00000024D452 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 32.97.182.139 Cc: qemu-stable@nongnu.org Subject: [Qemu-devel] [PATCH 047/108] qcow1: Validate L2 table size (CVE-2014-0222) X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 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-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Kevin Wolf Too large L2 table sizes cause unbounded allocations. Images actually created by qemu-img only have 512 byte or 4k L2 tables. To keep things consistent with cluster sizes, allow ranges between 512 bytes and 64k (in fact, down to 1 entry = 8 bytes is technically working, but L2 table sizes smaller than a cluster don't make a lot of sense). This also means that the number of bytes on the virtual disk that are described by the same L2 table is limited to at most 8k * 64k or 2^29, preventively avoiding any integer overflows. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf Reviewed-by: Benoit Canet (cherry picked from commit 42eb58179b3b215bb507da3262b682b8a2ec10b5) Signed-off-by: Michael Roth --- block/qcow.c | 8 ++++++++ tests/qemu-iotests/092 | 15 +++++++++++++++ tests/qemu-iotests/092.out | 11 +++++++++++ 3 files changed, 34 insertions(+) diff --git a/block/qcow.c b/block/qcow.c index 26bb923..8718ca5 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -138,6 +138,14 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } + /* l2_bits specifies number of entries; storing a uint64_t in each entry, + * so bytes = num_entries << 3. */ + if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) { + error_setg(errp, "L2 table size must be between 512 and 64k"); + ret = -EINVAL; + goto fail; + } + if (header.crypt_method > QCOW_CRYPT_AES) { error_setg(errp, "invalid encryption method in qcow header"); ret = -EINVAL; diff --git a/tests/qemu-iotests/092 b/tests/qemu-iotests/092 index d060e6f..fb8bacc 100755 --- a/tests/qemu-iotests/092 +++ b/tests/qemu-iotests/092 @@ -44,6 +44,7 @@ _supported_proto generic _supported_os Linux offset_cluster_bits=32 +offset_l2_bits=33 echo echo "== Invalid cluster size ==" @@ -57,6 +58,20 @@ poke_file "$TEST_IMG" "$offset_cluster_bits" "\x08" poke_file "$TEST_IMG" "$offset_cluster_bits" "\x11" { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +echo +echo "== Invalid L2 table size ==" +_make_test_img 64M +poke_file "$TEST_IMG" "$offset_l2_bits" "\xff" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +poke_file "$TEST_IMG" "$offset_l2_bits" "\x05" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +poke_file "$TEST_IMG" "$offset_l2_bits" "\x0e" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir + +# 1 << 0x1b = 2^31 / L2_CACHE_SIZE +poke_file "$TEST_IMG" "$offset_l2_bits" "\x1b" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir + # success, all done echo "*** done" rm -f $seq.full diff --git a/tests/qemu-iotests/092.out b/tests/qemu-iotests/092.out index 8bf8158..73918b3 100644 --- a/tests/qemu-iotests/092.out +++ b/tests/qemu-iotests/092.out @@ -10,4 +10,15 @@ qemu-io: can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and no file open, try 'help open' qemu-io: can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k no file open, try 'help open' + +== Invalid L2 table size == +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 +qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k +no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k +no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k +no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k +no file open, try 'help open' *** done