qemu/tests/qemu-iotests/195

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#!/usr/bin/env bash
# group: rw auto quick
#
# Test change-backing-file command
#
# Copyright (C) 2017 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 $seq"
status=1 # failure is the default!
_cleanup()
{
_cleanup_test_img
_rm_test_img "$TEST_IMG.mid"
}
trap "_cleanup; exit \$status" 0 1 2 3 15
# get standard environment, filters and checks
. ./common.rc
. ./common.filter
_supported_fmt qcow2
_supported_proto file fuse
do_run_qemu()
{
echo Testing: "$@"
$QEMU -nographic -qmp-pretty stdio -serial none "$@"
echo
}
run_qemu()
{
do_run_qemu "$@" 2>&1 | _filter_testdir | _filter_imgfmt | _filter_qemu \
| _filter_qmp | _filter_qemu_io \
| _filter_generated_node_ids
}
size=64M
TEST_IMG="$TEST_IMG.base" _make_test_img $size
iotests: Specify explicit backing format where sensible There are many existing qcow2 images that specify a backing file but no format. This has been the source of CVEs in the past, but has become more prominent of a problem now that libvirt has switched to -blockdev. With older -drive, at least the probing was always done by qemu (so the only risk of a changed format between successive boots of a guest was if qemu was upgraded and probed differently). But with newer -blockdev, libvirt must specify a format; if libvirt guesses raw where the image was formatted, this results in data corruption visible to the guest; conversely, if libvirt guesses qcow2 where qemu was using raw, this can result in potential security holes, so modern libvirt instead refuses to use images without explicit backing format. The change in libvirt to reject images without explicit backing format has pointed out that a number of tools have been far too reliant on probing in the past. It's time to set a better example in our own iotests of properly setting this parameter. iotest calls to create, rebase, and convert are all impacted to some degree. It's a bit annoying that we are inconsistent on command line - while all of those accept -o backing_file=...,backing_fmt=..., the shortcuts are different: create and rebase have -b and -F, while convert has -B but no -F. (amend has no shortcuts, but the previous patch just deprecated the use of amend to change backing chains). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200706203954.341758-9-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-06 23:39:52 +03:00
TEST_IMG="$TEST_IMG.mid" _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
_make_test_img -b "$TEST_IMG.mid" -F $IMGFMT
echo
echo "Change backing file of mid (opened read-only)"
echo
run_qemu -drive if=none,file="$TEST_IMG",backing.node-name=mid <<EOF
{"execute":"qmp_capabilities"}
{"execute":"change-backing-file", "arguments":{"device":"none0","image-node-name":"mid","backing-file":"/dev/null"}}
{"execute":"quit"}
EOF
TEST_IMG="$TEST_IMG.mid" _img_info
echo
echo "Change backing file of top (opened writable)"
echo
iotests: Specify explicit backing format where sensible There are many existing qcow2 images that specify a backing file but no format. This has been the source of CVEs in the past, but has become more prominent of a problem now that libvirt has switched to -blockdev. With older -drive, at least the probing was always done by qemu (so the only risk of a changed format between successive boots of a guest was if qemu was upgraded and probed differently). But with newer -blockdev, libvirt must specify a format; if libvirt guesses raw where the image was formatted, this results in data corruption visible to the guest; conversely, if libvirt guesses qcow2 where qemu was using raw, this can result in potential security holes, so modern libvirt instead refuses to use images without explicit backing format. The change in libvirt to reject images without explicit backing format has pointed out that a number of tools have been far too reliant on probing in the past. It's time to set a better example in our own iotests of properly setting this parameter. iotest calls to create, rebase, and convert are all impacted to some degree. It's a bit annoying that we are inconsistent on command line - while all of those accept -o backing_file=...,backing_fmt=..., the shortcuts are different: create and rebase have -b and -F, while convert has -B but no -F. (amend has no shortcuts, but the previous patch just deprecated the use of amend to change backing chains). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200706203954.341758-9-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-07-06 23:39:52 +03:00
TEST_IMG="$TEST_IMG.mid" _make_test_img -b "$TEST_IMG.base" -F $IMGFMT
run_qemu -drive if=none,file="$TEST_IMG",node-name=top <<EOF
{"execute":"qmp_capabilities"}
{"execute":"change-backing-file", "arguments":{"device":"none0","image-node-name":"top","backing-file":"/dev/null"}}
{"execute":"quit"}
EOF
_img_info
# success, all done
echo "*** done"
rm -f $seq.full
status=0