diff --git a/tools/test/stress2/misc/fsck14.sh b/tools/test/stress2/misc/fsck14.sh
new file mode 100755
index 000000000000..ddeb45a83e96
--- /dev/null
+++ b/tools/test/stress2/misc/fsck14.sh
@@ -0,0 +1,119 @@
+#!/bin/sh
+
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2023 Peter Holm <pho@FreeBSD.org>
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+
+# fsck -B test scenario with SUJ. -B implies "preen mode".
+
+# 'panic: ffs_blkfree_cg: bad size' seen:
+# https://people.freebsd.org/~pho/stress/log/log0465.txt
+# Fixed by: 220427da0e9b - Set UFS/FFS file type to snapshot before changing
+# its block pointers.
+
+[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
+. ../default.cfg
+mycc -o /tmp/flip -Wall -Wextra ../tools/flip.c || exit 2
+
+set -e
+md=/dev/md$mdstart
+prog=$(basename "$0" .sh)
+backup=/tmp/$prog.sh.diskimage.`date +%Y%m%dT%H%M%S`.gz
+log=/tmp/$prog.sh.log
+[ -c $md ] && mdconfig -d -u $mdstart
+dd if=/dev/zero of=$diskimage bs=128m count=1 status=none
+mdconfig -a -t vnode -f $diskimage -u $mdstart
+backups=`newfs -N $j $md | grep -A1 "super-block backups" | \
+    tail -1 | sed 's/,//g'`
+newfs -j $md > /dev/null 2>&1
+mount $md $mntpoint
+set +e
+
+jot 5000 | xargs -P0 -I% touch $mntpoint/a%
+while ! umount $mntpoint; do :; done
+/tmp/flip -n 10 $diskimage
+gzip < $diskimage > $backup
+fsync $diskimage $backup
+
+mount -f $md $mntpoint
+
+if ! fsck_ffs -B $md > $log 2>&1; then
+	grep MANUALLY $log
+	umount $mntpoint
+	fsck_ffs -fy $md > $log 2>&1; s=$?
+	grep -Eq "IS CLEAN|MARKED CLEAN" $log || {
+		cat $log
+		echo "fsck_ffs -f failed with exit code $s"
+		umount $mntpoint; mdconfig -d -u $mdstart
+		rm -f $log /tmp/flip $diskimage $backup
+		exit 1
+	}
+	mount $md $mntpoint
+fi
+
+jot 5000 | xargs -P0 -I% rm $mntpoint/a%
+jot 5000 | xargs -P0 -I% touch $mntpoint/b%
+
+ls -lR $mntpoint > /dev/null || {
+    echo "ls -lR $mntpoint failed after fsck -B"
+    umount $mntpoint; mdconfig -d -u $mdstart
+    rm -f $log /tmp/flip $diskimage $backup
+    exit 0 # For now, ignore non fatal errors
+}
+
+jot 5000 | xargs -P0 -I% rm $mntpoint/b% || {
+    echo "clean failed"
+    umount $mntpoint; mdconfig -d -u $mdstart
+    rm -f $log /tmp/flip $diskimage $backup
+    exit 0 # For now, ignore non fatal errors
+}
+umount $mntpoint
+
+r=0
+for i in `jot 4`; do
+	fsck_ffs -fy $diskimage > $log 2>&1; r=$?
+	if grep -qiE "super-?block.*failed" $log; then
+		for b in $backups; do
+			echo "fsck_ffs -b $b -fy $diskimage"
+			fsck_ffs -b $b -fy $diskimage > $log 2>&1
+			r=$?
+			grep -qiE "super-?block.*failed" $log ||
+			   break
+			echo "Checking next SB"
+		done
+	fi
+	[ $r -ne 0 ] && continue
+	grep -Eq "WAS MODIFIED" $log && continue
+	grep -Eq "CLEAN" $log && break
+done
+mount $md $mntpoint || exit 3
+ls -lR $mntpoint > /dev/null || { umount $mntpoint; mdconfig -d -u mdstart; echo "exit 4"; exit 4; }
+umount $mntpoint
+fsck_ffs -fy $md > $log 2>&1
+grep -Eq 'IS CLEAN|MARKED CLEAN' $log && s=0 || { s=1; cat $log; }
+mdconfig -d -u $mdstart
+rm -f $log /tmp/flip $diskimage $backup
+exit $s