[PATCH 2/3] libsepol: Check for an unset sensitivity in module_to_cil

[James Carter <jwcart2@gmail.com>]

It is possible for a base policy to have sensitivities for user
levels and ranges that are not set if the user is used in a require
block.

Check for an unset sensitivity before using it to look up the
name of the sensitivity to prevent a memory access error.

Signed-off-by: James Carter <jwcart2@gmail.com>
---
 libsepol/src/module_to_cil.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libsepol/src/module_to_cil.c b/libsepol/src/module_to_cil.c
index 41c2b051..56ebd9c8 100644
--- a/libsepol/src/module_to_cil.c
+++ b/libsepol/src/module_to_cil.c
@@ -520,6 +520,9 @@ static int semantic_level_to_cil(struct policydb *pdb, struct mls_semantic_level
 {
 	struct mls_semantic_cat *cat;
 
+	if (level->sens == 0)
+		return -1;
+
 	cil_printf("(%s ", pdb->p_sens_val_to_name[level->sens - 1]);
 
 	if (level->cat != NULL) {
@@ -2499,6 +2502,9 @@ static int level_to_cil(struct policydb *pdb, struct mls_level *level)
 {
 	struct ebitmap *map = &level->cat;
 
+	if (level->sens == 0)
+		return -1;
+
 	cil_printf("(%s", pdb->p_sens_val_to_name[level->sens - 1]);
 
 	if (!ebitmap_is_empty(map)) {
-- 
2.52.0