Re: [PATCH] xfs: Add test for CVE-2017-14340

Richard Wareing
2017-09-20T03:40:12Z

Darrick J. Wong <darrick.wong@oracle.com> wrote:

> On Tue, Sep 19, 2017 at 05:30:54PM -0700, Richard Wareing wrote:
>> 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.
>>
>> This bug was fixed via commit b31ff3cdf540110da4572e3e29bd172087af65cc
>
> Oooh, a commit id, nice! :)
>
>> on the main kernel tree.
>>
>> Signed-off-by: Richard Wareing <rwareing@fb.com>
>> ---
>> tests/xfs/431 | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> tests/xfs/431.out | 3 ++
>> tests/xfs/group | 1 +
>> 3 files changed, 90 insertions(+)
>> create mode 100755 tests/xfs/431
>> create mode 100644 tests/xfs/431.out
>>
>> diff --git a/tests/xfs/431 b/tests/xfs/431
>> new file mode 100755
>> index 0000000..f928abc
>> --- /dev/null
>> +++ b/tests/xfs/431
>> @@ -0,0 +1,86 @@
>> +#! /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.
>> +#
>> +#-----------------------------------------------------------------------
>> +# Copyright (c) 2017 YOUR NAME HERE. All Rights Reserved.
>
> Mr. HERE, please update this line! :)
>

Fixed in v2.

>> +#
>> +# 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
>> +_require_test
>> +
>
> Shouldn't we unset USE_EXTERNAL/SCRATCH_RTDEV here since the bug only
> affects non-rt xfses?
>

I tried playing around with this, but wasn't able to get it to
work. The best I think to do is create a "_require_no_realtime"
and skip the test if it's being run under a realtime test run.

>> +_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, we will check
>> +# exit code instead.
>> +$XFS_IO_PROG -c 'chattr +t' $SCRATCH_MNT &> /dev/null
>> +chattr_ret=$?
>> +
>> +# Erroring out here is fine, this would be desired behavior for
>> +# FSes without realtime devices present.
>> +if (( chattr_ret == 0)); then
>> + # Attempt to write/fsync data to file
>> + $XFS_IO_PROG -fc 'pwrite 0 1m' -c fsync $SCRATCH_MNT/testfile |
>> + tee -a $seqres.full | common_line_filter | _filter_xfs_io
>> +
>> + # Remove the rt inherit flag after we are done or xfs_repair
>> + # will fail.
>> + $XFS_IO_PROG -c 'chattr -t' $SCRATCH_MNT | tee -a $seqres.full 2>&1
>> +fi
>> +
>> +
>> +rm -f $SCRATCH_MNT/testfile
>> +
>> +# success, all done
>> +status=0
>> +exit
>> diff --git a/tests/xfs/431.out b/tests/xfs/431.out
>> new file mode 100644
>> index 0000000..8c14f11
>> --- /dev/null
>> +++ b/tests/xfs/431.out
>> @@ -0,0 +1,3 @@
>> +QA output created by 431
>> +wrote 1048576/1048576 bytes at offset 0
>> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
>> diff --git a/tests/xfs/group b/tests/xfs/group
>> index 0a449b9..3f97f02 100644
>> --- a/tests/xfs/group
>> +++ b/tests/xfs/group
>> @@ -427,3 +427,4 @@
>> 428 dangerous_fuzzers dangerous_scrub dangerous_online_repair
>> 429 dangerous_fuzzers dangerous_scrub dangerous_repair
>> 430 dangerous_fuzzers dangerous_scrub dangerous_online_repair
>> +431 quick
>
> This ought to have 'dangerous' too, so that everyone knows that it can
> crash an unpatched kernel.
>
> (After stable/distros have had a few weeks to fix this you could add it
> to the 'auto' group as well so that everyone will run it.)
>

Fixed in v3.

> --D
>
>> --
>> 2.9.5