tests/xfs/520

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2020 Red Hat, Inc.  All Rights Reserved.
#
# FS QA Test 520
#
# Verify kernel doesn't hang when mounting a crafted image
# with bad agf.freeblks metadata due to CVE-2020-12655.
#
# Also, check if
# commit d0c7feaf8767 ("xfs: add agf freeblocks verify in xfs_agf_verify")
# is included in the current kernel.
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

here=`pwd`
tmp=/tmp/$$
status=1	# failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15

_cleanup()
{
	cd /
	rm -f $tmp.*
	_scratch_unmount > /dev/null 2>&1
}

# get standard environment, filters and checks
. ./common/rc
. ./common/filter

# remove previous $seqres.full before test
rm -f $seqres.full

# real QA test starts here

_supported_fs xfs
_disable_dmesg_check
_require_check_dmesg
_require_scratch_nocheck

# Don't let the rtbitmap fill up the data device and screw up this test
unset USE_EXTERNAL

force_crafted_metadata() {
	_scratch_mkfs_xfs -f $fsdsopt "$4" >> $seqres.full 2>&1 || _fail "mkfs failed"
	_scratch_xfs_set_metadata_field "$1" "$2" "$3" >> $seqres.full 2>&1
	local kmsg="xfs/$seq: testing $1=$2 at $(date +"%F %T")"
	local mounted=0
	local hasmsg=0

	echo "${kmsg}" > /dev/kmsg
	_try_scratch_mount >> $seqres.full 2>&1 && mounted=1

	if [ $mounted -ne 0 ]; then
		dd if=/dev/zero of=$SCRATCH_MNT/test bs=65536 count=1 >> \
			$seqres.full 2>&1
		sync
	fi

	_dmesg_since_test_start | tac | sed -ne "0,\#${kmsg}#p" | tac | \
		egrep -q 'Metadata corruption detected at' && hasmsg=1

	_scratch_unmount > /dev/null 2>&1
	[ $mounted -eq 0 -o $hasmsg -eq 1 ] || \
		_fail "potential broken kernel (mounted=${mounted},hasmsg=${hasmsg})"
}

bigval=100000000
fsdsopt="-d agcount=1,size=64m"

force_crafted_metadata freeblks 0 "agf 0"
force_crafted_metadata longest $bigval "agf 0"
force_crafted_metadata length $bigval "agf 0"

_scratch_mkfs_xfs_supported -m reflink=1 >> $seqres.full 2>&1 && \
	force_crafted_metadata refcntblocks $bigval "agf 0" "-m reflink=1"

_scratch_mkfs_xfs_supported -m rmapbt=1 >> $seqres.full 2>&1 && \
	force_crafted_metadata rmapblocks $bigval "agf 0" "-m rmapbt=1"

echo "Silence is golden"

# success, all done
status=0
exit