[PATCH 4/5] libselinux: free data on selabel open failure

[Christian Göttsche <cgzones@xxxxxxxxxxxxxx>]

In case the init function for a selabel backend fails, free the possible
already allocated data:

    Direct leak of 16 byte(s) in 1 object(s) allocated from:
        #0 0x5e7e2bf001e3 in malloc (/tmp/destdir/usr/sbin/selabel_digest+0xc71e3)
        #1 0x7233764baa65 in selabel_media_init /home/christian/Coding/workspaces/selinux/libselinux/src/label_media.c:226:30
        #2 0x7233764ac1fe in selabel_open /home/christian/Coding/workspaces/selinux/libselinux/src/label.c:227:6
        #3 0x5e7e2bf3ebfc in main /home/christian/Coding/workspaces/selinux/libselinux/utils/selabel_digest.c:125:8
        #4 0x7233761856c9 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16

    SUMMARY: AddressSanitizer: 16 byte(s) leaked in 1 allocation(s).

Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
 libselinux/src/label.c                  | 5 +----
 libselinux/src/label_backends_android.c | 3 +++
 libselinux/src/label_db.c               | 3 +++
 libselinux/src/label_file.c             | 3 +++
 libselinux/src/label_media.c            | 3 +++
 libselinux/src/label_x.c                | 3 +++
 6 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/libselinux/src/label.c b/libselinux/src/label.c
index d2e703ef..06d743ec 100644
--- a/libselinux/src/label.c
+++ b/libselinux/src/label.c
@@ -225,10 +225,7 @@ struct selabel_handle *selabel_open(unsigned int backend,
 	rec->digest = selabel_is_digest_set(opts, nopts);
 
 	if ((*initfuncs[backend])(rec, opts, nopts)) {
-		if (rec->digest)
-			selabel_digest_fini(rec->digest);
-		free(rec->spec_file);
-		free(rec);
+		selabel_close(rec);
 		rec = NULL;
 	}
 
diff --git a/libselinux/src/label_backends_android.c b/libselinux/src/label_backends_android.c
index 33a17236..49a87686 100644
--- a/libselinux/src/label_backends_android.c
+++ b/libselinux/src/label_backends_android.c
@@ -246,6 +246,9 @@ static void closef(struct selabel_handle *rec)
 	struct spec *spec;
 	unsigned int i;
 
+	if (!data)
+		return;
+
 	for (i = 0; i < data->nspec; i++) {
 		spec = &data->spec_arr[i];
 		free(spec->property_key);
diff --git a/libselinux/src/label_db.c b/libselinux/src/label_db.c
index 2ff10b2f..40d5fc4a 100644
--- a/libselinux/src/label_db.c
+++ b/libselinux/src/label_db.c
@@ -178,6 +178,9 @@ db_close(struct selabel_handle *rec)
 	spec_t	       *spec;
 	unsigned int	i;
 
+	if (!catalog)
+		return;
+
 	for (i = 0; i < catalog->nspec; i++) {
 		spec = &catalog->specs[i];
 		free(spec->key);
diff --git a/libselinux/src/label_file.c b/libselinux/src/label_file.c
index 3b2bda97..2732972e 100644
--- a/libselinux/src/label_file.c
+++ b/libselinux/src/label_file.c
@@ -904,6 +904,9 @@ static void closef(struct selabel_handle *rec)
 	struct stem *stem;
 	unsigned int i;
 
+	if (!data)
+		return;
+
 	selabel_subs_fini(data->subs);
 	selabel_subs_fini(data->dist_subs);
 
diff --git a/libselinux/src/label_media.c b/libselinux/src/label_media.c
index fad5ea6d..94a58062 100644
--- a/libselinux/src/label_media.c
+++ b/libselinux/src/label_media.c
@@ -167,6 +167,9 @@ static void close(struct selabel_handle *rec)
 	struct spec *spec, *spec_arr = data->spec_arr;
 	unsigned int i;
 
+	if (!data)
+		return;
+
 	for (i = 0; i < data->nspec; i++) {
 		spec = &spec_arr[i];
 		free(spec->key);
diff --git a/libselinux/src/label_x.c b/libselinux/src/label_x.c
index bf569ca5..f994eefa 100644
--- a/libselinux/src/label_x.c
+++ b/libselinux/src/label_x.c
@@ -194,6 +194,9 @@ static void close(struct selabel_handle *rec)
 	struct spec *spec, *spec_arr = data->spec_arr;
 	unsigned int i;
 
+	if (!data)
+		return;
+
 	for (i = 0; i < data->nspec; i++) {
 		spec = &spec_arr[i];
 		free(spec->key);
-- 
2.43.0