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