SELinux: add more validity checks on policy load

Add more validity checks at policy load time to reject malformed
policies and prevent subsequent out-of-range indexing when in permissive
mode.  Resolves the NULL pointer dereference reported in
https://bugzilla.redhat.com/show_bug.cgi?id=357541.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index 844d310f4f1b..ed6fc687c66f 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -251,6 +251,9 @@ struct policydb {
 extern void policydb_destroy(struct policydb *p);
 extern int policydb_load_isids(struct policydb *p, struct sidtab *s);
 extern int policydb_context_isvalid(struct policydb *p, struct context *c);
+extern int policydb_class_isvalid(struct policydb *p, unsigned int class);
+extern int policydb_type_isvalid(struct policydb *p, unsigned int type);
+extern int policydb_role_isvalid(struct policydb *p, unsigned int role);
 extern int policydb_read(struct policydb *p, void *fp);
 
 #define PERM_SYMTAB_SIZE 32