#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2022 Red Hat, Inc.  All Rights Reserved.
#
# FS QA Test No. 680
#
# Test for the Dirty Pipe vulnerability (CVE-2022-0847) caused by an
# uninitialized  "pipe_buffer.flags" variable, which fixed by:
#   9d2231c5d74e ("lib/iov_iter: initialize "flags" in new pipe_buffer")
#
. ./common/preamble
_begin_fstest auto quick

# real QA test starts here
_supported_fs generic
_require_test
_require_user
_require_chmod
_require_test_program "splice2pipe"

localfile=$TEST_DIR/testfile.$seq
rm -f $localfile

# Create a file with 4k 0xff data, then make sure unprivileged user has readonly
# permission on it
$XFS_IO_PROG -f -t -c "pwrite 0 4k -S 0xff" $localfile >> $seqres.full 2>&1
chmod 0644 $localfile
# Test privileged user (xfstests generally run with root)
echo "Test privileged user:"
$here/src/splice2pipe $localfile 1 "AAAAAAAABBBBBBBB"
# Part of 0xff will be overwritten if there's CVE-2022-0847 bug
_hexdump $localfile

# Create a file with 4k 0xff data, then make sure unprivileged user has readonly
# permission on it
$XFS_IO_PROG -f -t -c "pwrite 0 4k -S 0xff" $localfile >> $seqres.full 2>&1
chmod 0644 $localfile
# Copy splice2pipe to a place which can be run by an unprivileged user (avoid
# something likes /root/xfstests/src/splice2pipe)
cp $here/src/splice2pipe $tmp.splice2pipe
# Test unprivileged user's privilege escalation
echo "Test unprivileged user:"
su ${qa_user} -c "$tmp.splice2pipe $localfile 1 AAAAAAAABBBBBBBB"
_hexdump $localfile

# success, all done
status=0
exit