tests/generic/193

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2008 Christoph Hellwig.
#
# FS QA Test No. 193
#
# Test permission checks in ->setattr
#
. ./common/preamble
_begin_fstest metadata auto quick

_register_cleanup "_cleanup_files"
tag="added by qa $seq"

#
# For some tests we need a secondary group for the qa_user.  Currently
# that's not available in the framework, so the tests using it are
# commented out.
#
#group2=foo

#
# Create two files, one owned by root, one by the qa_user
#
_create_files()
{
	touch $test_root
	touch $test_user
	chown ${qa_user}:${qa_user} $test_user
}

#
# Remove our files again
#
_cleanup_files()
{
	rm -f $test_user
	rm -f $test_root
}

_filter_files()
{
	sed -e "s,$test_root,test.root,g" -e "s,$test_user,test.user,g"
}

# Import common functions.
. ./common/filter

# real QA test starts here
_supported_fs generic

_require_test
_require_user
_require_chown

test_root=$TEST_DIR/$seq.$$.root
test_user=$TEST_DIR/$seq.$$.user

#
# make sure we have a normal umask set
#
umask 022

#
# Test the ATTR_UID case
#
echo
echo "testing ATTR_UID"
echo

_create_files

echo "user: chown root owned file to qa_user (should fail)"
su ${qa_user} -c "chown ${qa_user} $test_root" 2>&1 | _filter_files

echo "user: chown root owned file to root (should fail)"
su ${qa_user} -c "chown root $test_root" 2>&1 | _filter_files

echo "user: chown qa_user owned file to qa_user (should succeed)"
su ${qa_user} -c "chown ${qa_user} $test_user"

# this would work without _POSIX_CHOWN_RESTRICTED
echo "user: chown qa_user owned file to root (should fail)"
su ${qa_user} -c "chown root $test_user" 2>&1 | _filter_files

_cleanup_files

#
# Test the ATTR_GID case
#
echo
echo "testing ATTR_GID"
echo

_create_files

echo "user: chgrp root owned file to root (should fail)"
su ${qa_user} -c "chgrp root $test_root" 2>&1 | _filter_files

echo "user: chgrp qa_user owned file to root (should fail)"
su ${qa_user} -c "chgrp root $test_user" 2>&1 | _filter_files

echo "user: chgrp root owned file to qa_user (should fail)"
su ${qa_user} -c "chgrp ${qa_user} $test_root" 2>&1 | _filter_files

echo "user: chgrp qa_user owned file to qa_user (should succeed)"
su ${qa_user} -c "chgrp ${qa_user} $test_user"

#echo "user: chgrp qa_user owned file to secondary group (should succeed)"
#su ${qa_user} -c "chgrp ${group2} $test_user"

_cleanup_files

#
# Test the ATTR_MODE case
#
echo
echo "testing ATTR_MODE"
echo

_create_files

echo "user: chmod a+r on qa_user owned file (should succeed)"
su ${qa_user} -c "chmod a+r $test_user"

echo "user: chmod a+r on root owned file (should fail)"
su ${qa_user} -c "chmod a+r $test_root" 2>&1 | _filter_files

#
# Setup a file owned by the qa_user, but with a group ID that
# is not present in the qa_users group list (use root to make it easier for it)
# and mark it with set sgid bit
#
# From Posix (www.opengroup.org) for chmod:
#	"If the calling process does not have appropriate privileges, and
#	if the group ID of the file does not match the effective group ID
#	or one of the supplementary group IDs and if the file is a regular
#	file, bit S_ISGID (set-group-ID on execution) in the file's mode
#	shall be cleared upon successful return from chmod()."
# i.e.
# reg file + file's gid not in process' group set + no approp. privileges -> clear sgid
#
echo "check that the sgid bit is cleared"
chown ${qa_user}:root $test_user
chmod g+s $test_user

# and let the qa_user change permission bits
su ${qa_user} -c "chmod a+w $test_user"
stat -c '%A' $test_user

#
# Setup a file owned by the qa_user and with the suid bit set.
# A chmod by root should not clear the suid bit.
# There is nothing in Posix that says it should but just checking.
#
echo "check that suid bit is not cleared"
chmod u+s $test_user
chmod a+w $test_user
stat -c '%A' $test_user

_cleanup_files

_create_files
# Now test out the clear of suid/sgid for chown
#
# From Posix (www.opengroup.org) for chown:
#	"If the specified file is a regular file, one or more of the S_IXUSR,
#	S_IXGRP, or S_IXOTH bits of the file mode are set, and the process
#	does not have appropriate privileges, the set-user-ID (S_ISUID) and
#	set-group-ID (S_ISGID) bits of the file mode shall be cleared upon
#	successful return from chown(). If the specified file is a regular
#	file, one or more of the S_IXUSR, S_IXGRP, or S_IXOTH bits of the
#	file mode are set, and the process has appropriate privileges, it
#	is implementation-defined whether the set-user-ID and set-group-ID
#	bits are altered. If the chown() function is successfully invoked
#	on a file that is not a regular file and one or more of the S_IXUSR,
#	S_IXGRP, or S_IXOTH bits of the file mode are set, the set-user-ID
#	and set-group-ID bits may be cleared."
# i.e.
# reg file + exec-mode-bits set + no appropriate privileges -> clear suid,sgid
# reg file + exec-mode-bits set + appropriate privileges -> maybe clear suid,sgid
# non reg file + exec-mode-bits set + chown success on file (??) -> maybe clear suid/sgid
#
echo "check that suid/sgid bits are cleared after successful chown..."

echo "with no exec perm"
chmod ug+s $test_user
echo -n "before: "; stat -c '%A' $test_user
chown root $test_user
echo -n "after:  "; stat -c '%A' $test_user

echo "with user exec perm"
chmod ug+s $test_user
chmod u+x $test_user
echo -n "before: "; stat -c '%A' $test_user
chown root $test_user
echo -n "after:  "; stat -c '%A' $test_user

echo "with group exec perm"
chmod ug+s $test_user
chmod g+x $test_user
chmod u-x $test_user
echo -n "before: "; stat -c '%A' $test_user
chown root $test_user
echo -n "after:  "; stat -c '%A' $test_user

echo "with user+group exec perm"
chmod ug+s $test_user
chmod ug+x $test_user
echo -n "before: "; stat -c '%A' $test_user
chown root $test_user
echo -n "after:  "; stat -c '%A' $test_user

_cleanup_files

_create_files
# Now test out the clear of suid/sgid for truncate
#
echo "check that suid/sgid bits are cleared after successful truncate..."

echo "with no exec perm"
echo frobnozzle >> $test_user
chmod ug+s $test_user
echo -n "before: "; stat -c '%A' $test_user
su ${qa_user} -c "echo > $test_user"
echo -n "after:  "; stat -c '%A' $test_user

echo "with user exec perm"
echo frobnozzle >> $test_user
chmod ug+s $test_user
chmod u+x $test_user
echo -n "before: "; stat -c '%A' $test_user
su ${qa_user} -c "echo > $test_user"
echo -n "after:  "; stat -c '%A' $test_user

echo "with group exec perm"
echo frobnozzle >> $test_user
chmod ug+s $test_user
chmod g+x $test_user
chmod u-x $test_user
echo -n "before: "; stat -c '%A' $test_user
su ${qa_user} -c "echo > $test_user"
echo -n "after:  "; stat -c '%A' $test_user

echo "with user+group exec perm"
echo frobnozzle >> $test_user
chmod ug+s $test_user
chmod ug+x $test_user
echo -n "before: "; stat -c '%A' $test_user
su ${qa_user} -c "echo > $test_user"
echo -n "after:  "; stat -c '%A' $test_user

#
# Test ATTR_*TIMES_SET
#
echo
echo "testing ATTR_*TIMES_SET"
echo

_create_files

echo "user: touch qa_user file (should succeed)"
su ${qa_user} -c "touch $test_user"

echo "user: touch root file (should fail)"
su ${qa_user} -c "touch $test_root" 2>&1 | _filter_files

_cleanup_files

# success, all done
echo "*** done"
status=0