From 34d9d86de2d566b4c9ecd1ed0294edc0bb95bec6 Mon Sep 17 00:00:00 2001

From: Kevin Wolf <kwolf@redhat.com>

Date: Tue, 25 Mar 2014 14:23:27 +0100

Subject: [PATCH 20/49] qcow2: Check header_length (CVE-2014-0144)

RH-Author: Kevin Wolf <kwolf@redhat.com>

Message-id: <1395753835-7591-21-git-send-email-kwolf@redhat.com>

Patchwork-id: n/a

O-Subject: [virt-devel] [EMBARGOED RHEL-7.0 qemu-kvm PATCH 20/48] qcow2: Check header_length (CVE-2014-0144)

Bugzilla: 1079455

RH-Acked-by: Jeff Cody <jcody@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079455

Upstream status: Embargoed

This fixes an unbounded allocation for s->unknown_header_fields.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Conflicts:

tests/qemu-iotests/group

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

---

 block/qcow2.c              |   34 ++++++++++++++++++------

 tests/qemu-iotests/080     |   61 ++++++++++++++++++++++++++++++++++++++++++++

 tests/qemu-iotests/080.out |    9 ++++++

 tests/qemu-iotests/group   |    1 +

 4 files changed, 96 insertions(+), 9 deletions(-)

 create mode 100755 tests/qemu-iotests/080

 create mode 100644 tests/qemu-iotests/080.out

diff --git a/block/qcow2.c b/block/qcow2.c

index 18e136e..ea51f8e 100644

--- a/block/qcow2.c

+++ b/block/qcow2.c

@@ -460,6 +460,18 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,

     s->qcow_version = header.version;

+    /* Initialise cluster size */

+    if (header.cluster_bits < MIN_CLUSTER_BITS ||

+        header.cluster_bits > MAX_CLUSTER_BITS) {

+        error_setg(errp, "Unsupported cluster size: 2^%i", header.cluster_bits);

+        ret = -EINVAL;

+        goto fail;

+    }

+

+    s->cluster_bits = header.cluster_bits;

+    s->cluster_size = 1 << s->cluster_bits;

+    s->cluster_sectors = 1 << (s->cluster_bits - 9);

+

     /* Initialise version 3 header fields */

     if (header.version == 2) {

         header.incompatible_features    = 0;

@@ -473,6 +485,18 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,

         be64_to_cpus(&header.autoclear_features);

         be32_to_cpus(&header.refcount_order);

         be32_to_cpus(&header.header_length);

+

+        if (header.header_length < 104) {

+            error_setg(errp, "qcow2 header too short");

+            ret = -EINVAL;

+            goto fail;

+        }

+    }

+

+    if (header.header_length > s->cluster_size) {

+        error_setg(errp, "qcow2 header exceeds cluster size");

+        ret = -EINVAL;

+        goto fail;

     }

     if (header.header_length > sizeof(header)) {

@@ -529,12 +553,6 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,

     }

     s->refcount_order = header.refcount_order;

-    if (header.cluster_bits < MIN_CLUSTER_BITS ||

-        header.cluster_bits > MAX_CLUSTER_BITS) {

-        error_setg(errp, "Unsupported cluster size: 2^%i", header.cluster_bits);

-        ret = -EINVAL;

-        goto fail;

-    }

     if (header.crypt_method > QCOW_CRYPT_AES) {

         error_setg(errp, "Unsupported encryption method: %i",

                    header.crypt_method);

@@ -545,9 +563,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,

     if (s->crypt_method_header) {

         bs->encrypted = 1;

     }

-    s->cluster_bits = header.cluster_bits;

-    s->cluster_size = 1 << s->cluster_bits;

-    s->cluster_sectors = 1 << (s->cluster_bits - 9);

+

     s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */

     s->l2_size = 1 << s->l2_bits;

     bs->total_sectors = header.size / 512;

diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080

new file mode 100755

index 0000000..6512701

--- /dev/null

+++ b/tests/qemu-iotests/080

@@ -0,0 +1,61 @@

+#!/bin/bash

+#

+# qcow2 format input validation tests

+#

+# Copyright (C) 2013 Red Hat, Inc.

+#

+# This program is free software; you can redistribute it and/or modify

+# it under the terms of the GNU General Public License as published by

+# the Free Software Foundation; either version 2 of the License, or

+# (at your option) any later version.

+#

+# This program is distributed in the hope that it will be useful,

+# but WITHOUT ANY WARRANTY; without even the implied warranty of

+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+# GNU General Public License for more details.

+#

+# You should have received a copy of the GNU General Public License

+# along with this program.  If not, see <http://www.gnu.org/licenses/>.

+#

+

+# creator

+owner=kwolf@redhat.com

+

+seq=`basename $0`

+echo "QA output created by $seq"

+

+here=`pwd`

+tmp=/tmp/$$

+status=1	# failure is the default!

+

+_cleanup()

+{

+	_cleanup_test_img

+}

+trap "_cleanup; exit \$status" 0 1 2 3 15

+

+# get standard environment, filters and checks

+. ./common.rc

+. ./common.filter

+

+_supported_fmt qcow2

+_supported_proto generic

+_supported_os Linux

+

+header_size=104

+offset_header_size=100

+offset_ext_magic=$header_size

+offset_ext_size=$((header_size + 4))

+

+echo

+echo "== Huge header size =="

+_make_test_img 64M

+poke_file "$TEST_IMG" "$offset_header_size" "\xff\xff\xff\xff"

+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir

+poke_file "$TEST_IMG" "$offset_header_size" "\x7f\xff\xff\xff"

+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir

+

+# success, all done

+echo "*** done"

+rm -f $seq.full

+status=0

diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out

new file mode 100644

index 0000000..41a166a

--- /dev/null

+++ b/tests/qemu-iotests/080.out

@@ -0,0 +1,9 @@

+QA output created by 080

+

+== Huge header size ==

+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 

+qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size

+no file open, try 'help open'

+qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size

+no file open, try 'help open'

+*** done

diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group

index 7d0d07e..fc34194 100644

--- a/tests/qemu-iotests/group

+++ b/tests/qemu-iotests/group

@@ -75,6 +75,7 @@

 077 rw auto

 078 rw auto

 079 rw auto

+080 rw auto

 082 rw auto quick

 086 rw auto quick

 088 rw auto

-- 

1.7.1