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parallels: Fix catalog size integer overflow (CVE-2014-0143)
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The first test case would cause a huge memory allocation, leading to a
qemu abort; the second one to a too small malloc() for the catalog
(smaller than s->catalog_size), which causes a read-only out-of-bounds
array access and on big endian hosts an endianess conversion for an
undefined memory area.

The sample image used here is not an original Parallels image. It was
created using an hexeditor on the basis of the struct that qemu uses.
Good enough for trying to crash the driver, but not for ensuring
compatibility.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit afbcc40)

Conflicts:
	tests/qemu-iotests/group

*fixed mismatches in group file

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
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kevmw authored and mdroth committed Jul 3, 2014
1 parent cfa8008 commit 750336b
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Showing 6 changed files with 97 additions and 1 deletion.
7 changes: 6 additions & 1 deletion block/parallels.c
Expand Up @@ -49,7 +49,7 @@ typedef struct BDRVParallelsState {
CoMutex lock;

uint32_t *catalog_bitmap;
int catalog_size;
unsigned int catalog_size;

int tracks;
} BDRVParallelsState;
Expand Down Expand Up @@ -94,6 +94,11 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
s->tracks = le32_to_cpu(ph.tracks);

s->catalog_size = le32_to_cpu(ph.catalog_entries);
if (s->catalog_size > INT_MAX / 4) {
error_setg(errp, "Catalog too large");
ret = -EFBIG;
goto fail;
}
s->catalog_bitmap = g_malloc(s->catalog_size * 4);

ret = bdrv_pread(bs->file, 64, s->catalog_bitmap, s->catalog_size * 4);
Expand Down
69 changes: 69 additions & 0 deletions tests/qemu-iotests/076
@@ -0,0 +1,69 @@
#!/bin/bash
#
# parallels 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 parallels
_supported_proto generic
_supported_os Linux

catalog_entries_offset=$((0x20))
nb_sectors_offset=$((0x24))

echo
echo "== Read from a valid (enough) image =="
_use_sample_img fake.parallels.bz2
{ $QEMU_IO -c "read -P 0x11 0 64k" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir

echo
echo "== Negative catalog size =="
_use_sample_img fake.parallels.bz2
poke_file "$TEST_IMG" "$catalog_entries_offset" "\xff\xff\xff\xff"
{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir

echo
echo "== Overflow in catalog allocation =="
_use_sample_img fake.parallels.bz2
poke_file "$TEST_IMG" "$nb_sectors_offset" "\xff\xff\xff\xff"
poke_file "$TEST_IMG" "$catalog_entries_offset" "\x01\x00\x00\x40"
{ $QEMU_IO -c "read 64M 64M" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir

# success, all done
echo "*** done"
rm -f $seq.full
status=0
14 changes: 14 additions & 0 deletions tests/qemu-iotests/076.out
@@ -0,0 +1,14 @@
QA output created by 076

== Read from a valid (enough) image ==
read 65536/65536 bytes at offset 0
64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

== Negative catalog size ==
qemu-io: can't open device TEST_DIR/fake.parallels: Catalog too large
no file open, try 'help open'

== Overflow in catalog allocation ==
qemu-io: can't open device TEST_DIR/fake.parallels: Catalog too large
no file open, try 'help open'
*** done
7 changes: 7 additions & 0 deletions tests/qemu-iotests/common
Expand Up @@ -131,6 +131,7 @@ check options
-bochs test bochs
-cow test cow
-cloop test cloop
-parallels test parallels
-qcow test qcow
-qcow2 test qcow2
-qed test qed
Expand Down Expand Up @@ -181,6 +182,12 @@ testlist options
xpand=false
;;

-parallels)
IMGFMT=parallels
IMGFMT_GENERIC=false
xpand=false
;;

-qcow)
IMGFMT=qcow
xpand=false
Expand Down
1 change: 1 addition & 0 deletions tests/qemu-iotests/group
Expand Up @@ -78,6 +78,7 @@
070 rw auto
073 rw auto
075 rw auto
076 auto
078 rw auto
080 rw auto
088 rw auto
Binary file added tests/qemu-iotests/sample_images/fake.parallels.bz2
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