generic: test access controls on the fs-verity ioctls

Test access controls on the fs-verity ioctls.  FS_IOC_MEASURE_VERITY is
allowed on any file, whereas FS_IOC_ENABLE_VERITY requires write access.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

tests/generic/573

@@ -0,0 +1,73 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright 2018 Google LLC
+#
+# FS QA Test generic/573
+#
+# Test access controls on the fs-verity ioctls.  FS_IOC_MEASURE_VERITY is
+# allowed on any file, whereas FS_IOC_ENABLE_VERITY requires write access.
+#
+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
+. ./common/verity
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_scratch_verity
+_require_user
+_require_chattr ia
+
+_scratch_mkfs_verity &>> $seqres.full
+_scratch_mount
+fsv_file=$SCRATCH_MNT/file.fsv
+
+_fsv_scratch_begin_subtest "FS_IOC_ENABLE_VERITY doesn't require root"
+echo foo > $fsv_file
+chmod 666 $fsv_file
+_user_do "$FSVERITY_PROG enable $fsv_file"
+
+_fsv_scratch_begin_subtest "FS_IOC_ENABLE_VERITY requires write access"
+echo foo > $fsv_file >> $seqres.full
+chmod 444 $fsv_file
+_user_do "$FSVERITY_PROG enable $fsv_file" |& _filter_scratch
+
+_fsv_scratch_begin_subtest "FS_IOC_ENABLE_VERITY requires !append-only"
+echo foo > $fsv_file >> $seqres.full
+$CHATTR_PROG +a $fsv_file
+$FSVERITY_PROG enable $fsv_file |& _filter_scratch
+$CHATTR_PROG -a $fsv_file
+
+_fsv_scratch_begin_subtest "FS_IOC_ENABLE_VERITY requires !immutable"
+echo foo > $fsv_file >> $seqres.full
+$CHATTR_PROG +i $fsv_file
+$FSVERITY_PROG enable $fsv_file |& _filter_scratch
+$CHATTR_PROG -i $fsv_file
+
+_fsv_scratch_begin_subtest "FS_IOC_MEASURE_VERITY doesn't require root"
+_fsv_create_enable_file $fsv_file >> $seqres.full
+chmod 444 $fsv_file
+su $qa_user -c "$FSVERITY_PROG measure $fsv_file" >> $seqres.full
+
+# success, all done
+status=0
+exit

tests/generic/573.out

@@ -0,0 +1,14 @@
+QA output created by 573
+
+# FS_IOC_ENABLE_VERITY doesn't require root
+
+# FS_IOC_ENABLE_VERITY requires write access
+Permission denied
+
+# FS_IOC_ENABLE_VERITY requires !append-only
+ERROR: FS_IOC_ENABLE_VERITY failed on 'SCRATCH_MNT/file.fsv': Operation not permitted
+
+# FS_IOC_ENABLE_VERITY requires !immutable
+ERROR: FS_IOC_ENABLE_VERITY failed on 'SCRATCH_MNT/file.fsv': Operation not permitted
+
+# FS_IOC_MEASURE_VERITY doesn't require root

tests/generic/group

@@ -575,3 +575,4 @@
 570 auto quick rw swap
 571 auto quick
 572 auto quick verity
+573 auto quick verity