#! /bin/bash
# FS QA Test 431
#
# Verify kernel doesn't panic when user attempts to set realtime flags
# on non-realtime FS, using kernel compiled with CONFIG_XFS_RT.  Unpatched
# kernels will panic during this test.  Kernels not compiled with
# CONFIG_XFS_RT should pass test.
#
# See CVE-2017-14340 for more information.
#
#-----------------------------------------------------------------------
# Copyright (c) 2017 Facebook, Inc.  All Rights Reserved.
#
# 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.
#
# This program is distributed in the hope that it would 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, write the Free Software Foundation,
# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#-----------------------------------------------------------------------
#

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.*
}

# 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

# Modify as appropriate.
_supported_fs xfs
_supported_os Linux
_require_xfs_io_command "chattr"
_require_xfs_io_command "fsync"
_require_xfs_io_command "pwrite"
_require_scratch

_scratch_mkfs >/dev/null 2>&1
_scratch_mount

# Set realtime inherit flag on scratch mount, suppress output
# as this may simply error out on future kernels
$XFS_IO_PROG -c 'chattr +t' $SCRATCH_MNT &> /dev/null

# Check if 't' is actually set, as xfs_io returns 0 even when it fails to set
# an attribute. And erroring out here is fine, this would be desired behavior
# for FSes without realtime devices present.
if $XFS_IO_PROG -c 'lsattr' $SCRATCH_MNT | grep -q 't'; then
	# Attempt to write/fsync data to file
	$XFS_IO_PROG -fc 'pwrite 0 1m' -c fsync $SCRATCH_MNT/testfile |
		tee -a $seqres.full | _filter_xfs_io

	# Remove the testfile and rt inherit flag after we are done or
	# xfs_repair will fail.
	rm -f $SCRATCH_MNT/testfile
	$XFS_IO_PROG -c 'chattr -t' $SCRATCH_MNT | tee -a $seqres.full 2>&1
fi

# success, all done
status=0
exit