[PATCH v2] fixfiles: Unmount temporary bind mounts on SIGINT

[Petr Lautrbach <plautrba@redhat.com>]

`fixfiles -M relabel` temporary bind mounts filestems before relabeling
but it leaves a directory mounted in /tmp/tmp.XXXX when a user hits
CTRL-C. It means that if the user run `fixfiles -M relabel` again and
answered Y to clean out /tmp directory, it would remove all data from
mounted fs.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2125355

Signed-off-by: Petr Lautrbach <plautrba@redhat.com>
---
v2:

- set trap on EXIT instead of SIGINT

 policycoreutils/scripts/fixfiles | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/policycoreutils/scripts/fixfiles b/policycoreutils/scripts/fixfiles
index c72ca0eb9d61..d763fa83eefd 100755
--- a/policycoreutils/scripts/fixfiles
+++ b/policycoreutils/scripts/fixfiles
@@ -207,6 +207,15 @@ rpm -q --qf '[%{FILESTATES} %{FILENAMES}\n]' "$1" | grep '^0 ' | cut -f2- -d ' '
 [ ${PIPESTATUS[0]} != 0 ] && echo "$1 not found" >/dev/stderr
 }
 
+# unmount tmp bind mount before exit
+umount_TMP_MOUNT() {
+	if [ -n "$TMP_MOUNT" ]; then
+	     umount "${TMP_MOUNT}${m}" || exit 130
+	     rm -rf "${TMP_MOUNT}" || echo "Error cleaning up."
+	fi
+	exit 130
+}
+
 #
 # restore
 # if called with -n will only check file context
@@ -251,6 +260,7 @@ case "$RESTORE_MODE" in
 	    else
 	        # we bind mount so we can fix the labels of files that have already been
 	        # mounted over
+	        trap umount_TMP_MOUNT EXIT
 	        for m in `echo $FILESYSTEMSRW`; do
 	            TMP_MOUNT="$(mktemp -d)"
 	            test -z ${TMP_MOUNT+x} && echo "Unable to find temporary directory!" && exit 1
@@ -261,6 +271,7 @@ case "$RESTORE_MODE" in
 	            umount "${TMP_MOUNT}${m}" || exit 1
 	            rm -rf "${TMP_MOUNT}" || echo "Error cleaning up."
 	        done;
+	        trap EXIT
 	    fi
 	else
 	    echo >&2 "fixfiles: No suitable file systems found"
-- 
2.37.3