qemu-e2k/tests/qemu-iotests/034
Eric Blake b66ff2c298 iotests: Specify explicit backing format where sensible
There are many existing qcow2 images that specify a backing file but
no format.  This has been the source of CVEs in the past, but has
become more prominent of a problem now that libvirt has switched to
-blockdev.  With older -drive, at least the probing was always done by
qemu (so the only risk of a changed format between successive boots of
a guest was if qemu was upgraded and probed differently).  But with
newer -blockdev, libvirt must specify a format; if libvirt guesses raw
where the image was formatted, this results in data corruption visible
to the guest; conversely, if libvirt guesses qcow2 where qemu was
using raw, this can result in potential security holes, so modern
libvirt instead refuses to use images without explicit backing format.

The change in libvirt to reject images without explicit backing format
has pointed out that a number of tools have been far too reliant on
probing in the past.  It's time to set a better example in our own
iotests of properly setting this parameter.

iotest calls to create, rebase, and convert are all impacted to some
degree.  It's a bit annoying that we are inconsistent on command line
- while all of those accept -o backing_file=...,backing_fmt=..., the
shortcuts are different: create and rebase have -b and -F, while
convert has -B but no -F.  (amend has no shortcuts, but the previous
patch just deprecated the use of amend to change backing chains).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-9-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-14 15:18:59 +02:00

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#!/usr/bin/env bash
#
# Test bdrv_pwrite_zeroes with backing files (see also 154)
#
# Copyright (C) 2012 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 $seq"
status=1 # failure is the default!
_cleanup()
{
_cleanup_test_img
}
trap "_cleanup; exit \$status" 0 1 2 3 15
# get standard environment, filters and checks
. ./common.rc
. ./common.filter
_supported_fmt qcow qcow2 vmdk qed
_supported_proto file
_supported_os Linux
_unsupported_imgopts "subformat=monolithicFlat" \
"subformat=twoGbMaxExtentFlat" \
"subformat=twoGbMaxExtentSparse" \
"subformat=streamOptimized"
CLUSTER_SIZE=4k
size=128M
echo
echo "== creating backing file for COW tests =="
TEST_IMG_SAVE="$TEST_IMG"
TEST_IMG="$TEST_IMG.base"
_make_test_img $size
$QEMU_IO -c "write -P 0x55 0 1M" "$TEST_IMG" | _filter_qemu_io
TEST_IMG="$TEST_IMG_SAVE"
_make_test_img -b "$TEST_IMG.base" -F $IMGFMT 6G
echo
echo "== zero write with backing file =="
$QEMU_IO -c "write -z 64k 192k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -z 513k 13k" "$TEST_IMG" | _filter_qemu_io
_check_test_img
echo
echo "== verifying patterns (3) =="
$QEMU_IO -c "read -P 0x55 0 64k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x0 64k 192k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x55 256k 257k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x0 513k 13k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x55 526k 498k" "$TEST_IMG" | _filter_qemu_io
echo
echo "== overwriting zero cluster =="
$QEMU_IO -c "write -P 0xa 60k 8k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -P 0xb 64k 8k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -P 0xc 76k 4k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -P 0xd 252k 8k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "write -P 0xe 248k 8k" "$TEST_IMG" | _filter_qemu_io
_check_test_img
echo
echo "== verifying patterns (4) =="
$QEMU_IO -c "read -P 0x55 0 60k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0xa 60k 4k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0xb 64k 8k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x0 72k 4k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0xc 76k 4k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x0 80k 168k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0xe 248k 8k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0xd 256k 4k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x55 260k 64k" "$TEST_IMG" | _filter_qemu_io
echo
echo "== re-zeroing overwritten area =="
$QEMU_IO -c "write -z 64k 192k" "$TEST_IMG" | _filter_qemu_io
_check_test_img
echo
echo "== verifying patterns (5) =="
$QEMU_IO -c "read -P 0x55 0 60k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0xa 60k 4k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x0 64k 192k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0xd 256k 4k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x55 260k 253k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x0 513k 13k" "$TEST_IMG" | _filter_qemu_io
$QEMU_IO -c "read -P 0x55 526k 498k" "$TEST_IMG" | _filter_qemu_io
# success, all done
echo "*** done"
rm -f $seq.full
status=0