SELinux: add default_type statements

Because Fedora shipped userspace based on my development tree we now
have policy version 27 in the wild defining only default user, role, and
range.  Thus to add default_type we need a policy.28.

Signed-off-by: Eric Paris <eparis@redhat.com>

4 files changed, 33 insertions, 6 deletions

diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index ba53400195c0..dde2005407aa 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -32,13 +32,14 @@
 #define POLICYDB_VERSION_FILENAME_TRANS 25
 #define POLICYDB_VERSION_ROLETRANS      26
 #define POLICYDB_VERSION_NEW_OBJECT_DEFAULTS    27
+#define POLICYDB_VERSION_DEFAULT_TYPE   28
 
 /* Range of policy versions we understand*/
 #define POLICYDB_VERSION_MIN   POLICYDB_VERSION_BASE
 #ifdef CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX
 #define POLICYDB_VERSION_MAX    CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX_VALUE
 #else
-#define POLICYDB_VERSION_MAX    POLICYDB_VERSION_NEW_OBJECT_DEFAULTS
+#define POLICYDB_VERSION_MAX    POLICYDB_VERSION_DEFAULT_TYPE
 #endif
 
 /* Mask for just the mount related flags */
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 2bb9c2fd5f1a..9cd9b7c661ec 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -138,6 +138,11 @@ static struct policydb_compat_info policydb_compat[] = {
                 .sym_num        = SYM_NUM,
                 .ocon_num       = OCON_NUM,
         },
+        {
+                .version        = POLICYDB_VERSION_DEFAULT_TYPE,
+                .sym_num        = SYM_NUM,
+                .ocon_num       = OCON_NUM,
+        },
 };
 
 static struct policydb_compat_info *policydb_lookup_compat(int version)
@@ -1321,6 +1326,13 @@ static int class_read(struct policydb *p, struct hashtab *h, void *fp)
                 cladatum->default_range = le32_to_cpu(buf[2]);
         }
 
+        if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) {
+                rc = next_entry(buf, fp, sizeof(u32) * 1);
+                if (rc)
+                        goto bad;
+                cladatum->default_type = le32_to_cpu(buf[0]);
+        }
+
         rc = hashtab_insert(h, key, cladatum);
         if (rc)
                 goto bad;
@@ -2857,6 +2869,13 @@ static int class_write(void *vkey, void *datum, void *ptr)
                         return rc;
         }
 
+        if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) {
+                buf[0] = cpu_to_le32(cladatum->default_type);
+                rc = put_entry(buf, sizeof(uint32_t), 1, fp);
+                if (rc)
+                        return rc;
+        }
+
         return 0;
 }
 
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index a949f1ad43bb..da637471d4ce 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -60,11 +60,12 @@ struct class_datum {
         struct symtab permissions;      /* class-specific permission symbol table */
         struct constraint_node *constraints;    /* constraints on class permissions */
         struct constraint_node *validatetrans;  /* special transition rules */
-        /* Options how a new object user and role should be decided */
+/* Options how a new object user, role, and type should be decided */
 #define DEFAULT_SOURCE         1
 #define DEFAULT_TARGET         2
         char default_user;
         char default_role;
+        char default_type;
 /* Options how a new object range should be decided */
 #define DEFAULT_SOURCE_LOW     1
 #define DEFAULT_SOURCE_HIGH    2
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 2ea108c2c048..1ded0ec7e8c2 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1472,12 +1472,18 @@ static int security_compute_sid(u32 ssid,
         }
 
         /* Set the type to default values. */
-        if ((tclass == policydb.process_class) || (sock == true)) {
-                /* Use the type of process. */
+        if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
                 newcontext.type = scontext->type;
-        } else {
-                /* Use the type of the related object. */
+        } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
                 newcontext.type = tcontext->type;
+        } else {
+                if ((tclass == policydb.process_class) || (sock == true)) {
+                        /* Use the type of process. */
+                        newcontext.type = scontext->type;
+                } else {
+                        /* Use the type of the related object. */
+                        newcontext.type = tcontext->type;
+                }
         }
 
         /* Look for a type transition/member/change rule. */