From d4d0955c67f5b928ef134ee7e7e23a9c40a266ea Mon Sep 17 00:00:00 2001
From: James Carter <jwcart2@gmail.com>
Date: Tue, 16 Mar 2021 14:30:02 -0400
Subject: [PATCH] libsepol: Write "NO_IDENTIFIER" for empty constraint
 expression

If a role attribute with no roles associated with it is used in a
constraint expression, then the role bitmap will be empty. This is
not a problem for the kernel, but does cause problems when
converting a kernel policy to policy.conf.

When creating a policy.conf from a kernel policy, if an empty bitmap
is encountered, use the string "NO_IDENTIFIER". An error will occur
if an attempt is made to compile the resulting policy, but this is
better than exiting with an error without creating a policy.conf.

Signed-off-by: James Carter <jwcart2@gmail.com>
---
 libsepol/src/kernel_to_conf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libsepol/src/kernel_to_conf.c b/libsepol/src/kernel_to_conf.c
index ea58a026501f..cd5a517abb59 100644
--- a/libsepol/src/kernel_to_conf.c
+++ b/libsepol/src/kernel_to_conf.c
@@ -186,7 +186,7 @@ static char *constraint_expr_to_str(struct policydb *pdb, struct constraint_expr
 					names = ebitmap_to_str(&curr->names, pdb->p_role_val_to_name, 1);
 				}
 				if (!names) {
-					goto exit;
+					names = strdup("NO_IDENTIFIER");
 				}
 				new_val = create_str("%s %s %s", 3, attr1, op, names);
 				free(names);
-- 
2.32.0