[PATCH v2] libselinux: avoid logs in get_ordered_context_list() without policy

[Christian Göttsche <cgzones@xxxxxxxxxxxxxx>]

If no policy has been loaded yet and thus the current context is still
"kernel" avoid logging failures in get_ordered_context_list(), like:

    get_ordered_context_list:  error in processing configuration file /etc/selinux/debian/contexts/users/root
    get_ordered_context_list:  error in processing configuration file /etc/selinux/debian/contexts/default_contexts

Move the context parsing from get_context_user() to its caller
get_ordered_context_list(), so an invalid context is not treated as an
get_context_user() failure and not logged.

Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
v2:
  - move the context parsing from get_context_user() to its caller
  - add Signed-off-by
---
 libselinux/src/get_context_list.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/libselinux/src/get_context_list.c b/libselinux/src/get_context_list.c
index 7e23be05..0ad24654 100644
--- a/libselinux/src/get_context_list.c
+++ b/libselinux/src/get_context_list.c
@@ -130,7 +130,7 @@ static int is_in_reachable(char **reachable, const char *usercon_str)
 }
 
 static int get_context_user(FILE * fp,
-			     const char * fromcon,
+			     context_t fromcon,
 			     const char * user,
 			     char ***reachable,
 			     unsigned int *nreachable)
@@ -146,7 +146,6 @@ static int get_context_user(FILE * fp,
 	char **new_reachable = NULL;
 	char *usercon_str;
 	const char *usercon_str2;
-	context_t con;
 	context_t usercon;
 
 	int rc;
@@ -155,14 +154,10 @@ static int get_context_user(FILE * fp,
 
 	/* Extract the role and type of the fromcon for matching.
 	   User identity and MLS range can be variable. */
-	con = context_new(fromcon);
-	if (!con)
-		return -1;
-	fromrole = context_role_get(con);
-	fromtype = context_type_get(con);
-	fromlevel = context_range_get(con);
+	fromrole = context_role_get(fromcon);
+	fromtype = context_type_get(fromcon);
+	fromlevel = context_range_get(fromcon);
 	if (!fromrole || !fromtype) {
-		context_free(con);
 		return -1;
 	}
 
@@ -296,7 +291,6 @@ static int get_context_user(FILE * fp,
 	rc = 0;
 
       out:
-	context_free(con);
 	free(line);
 	return rc;
 }
@@ -418,6 +412,7 @@ int get_ordered_context_list(const char *user,
 	char *fname = NULL;
 	size_t fname_len;
 	const char *user_contexts_path = selinux_user_contexts_path();
+	context_t con = NULL;
 
 	if (!fromcon) {
 		/* Get the current context and use it for the starting context */
@@ -427,6 +422,10 @@ int get_ordered_context_list(const char *user,
 		fromcon = backup_fromcon;
 	}
 
+	con = context_new(fromcon);
+	if (!con)
+		goto failsafe;
+
 	/* Determine the ordering to apply from the optional per-user config
 	   and from the global config. */
 	fname_len = strlen(user_contexts_path) + strlen(user) + 2;
@@ -437,7 +436,7 @@ int get_ordered_context_list(const char *user,
 	fp = fopen(fname, "re");
 	if (fp) {
 		__fsetlocking(fp, FSETLOCKING_BYCALLER);
-		rc = get_context_user(fp, fromcon, user, &reachable, &nreachable);
+		rc = get_context_user(fp, con, user, &reachable, &nreachable);
 
 		fclose(fp);
 		if (rc < 0 && errno != ENOENT) {
@@ -451,7 +450,7 @@ int get_ordered_context_list(const char *user,
 	fp = fopen(selinux_default_context_path(), "re");
 	if (fp) {
 		__fsetlocking(fp, FSETLOCKING_BYCALLER);
-		rc = get_context_user(fp, fromcon, user, &reachable, &nreachable);
+		rc = get_context_user(fp, con, user, &reachable, &nreachable);
 		fclose(fp);
 		if (rc < 0 && errno != ENOENT) {
 			selinux_log(SELINUX_ERROR,
@@ -472,6 +471,7 @@ int get_ordered_context_list(const char *user,
 	else
 		freeconary(reachable);
 
+	context_free(con);
 	freecon(backup_fromcon);
 
 	return rc;
-- 
2.43.0