apparmor: fix: kzalloc perms tables for shared dfas

Currently the permstables of the shared dfas are not shared, and need
to be allocated and copied. In the future this should be addressed
with a larger rework on dfa and pdb ref counts and structure sharing.

BugLink: http://bugs.launchpad.net/bugs/2017903
Fixes: 217af7e2 ("apparmor: refactor profile rules and attachments")
Cc: stable@vger.kernel.org
Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Jon Tourville <jontourville@me.com>

security/apparmor/policy.c

@@ -589,7 +589,15 @@ struct aa_profile *aa_alloc_null(struct aa_profile *parent, const char *name,
 	profile->label.flags |= FLAG_NULL;
 	rules = list_first_entry(&profile->rules, typeof(*rules), list);
 	rules->file.dfa = aa_get_dfa(nulldfa);
+	rules->file.perms = kcalloc(2, sizeof(struct aa_perms), GFP_KERNEL);
+	if (!rules->file.perms)
+		goto fail;
+	rules->file.size = 2;
 	rules->policy.dfa = aa_get_dfa(nulldfa);
+	rules->policy.perms = kcalloc(2, sizeof(struct aa_perms), GFP_KERNEL);
+	if (!rules->policy.perms)
+		goto fail;
+	rules->policy.size = 2;
 
 	if (parent) {
 		profile->path_flags = parent->path_flags;
@@ -600,6 +608,11 @@ struct aa_profile *aa_alloc_null(struct aa_profile *parent, const char *name,
 	}
 
 	return profile;
+
+fail:
+	aa_free_profile(profile);
+
+	return NULL;
 }
 
 /**

security/apparmor/policy_unpack.c

@@ -982,9 +982,14 @@ static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
 				goto fail;
 			}
 		}
-	} else
+	} else {
 		rules->policy.dfa = aa_get_dfa(nulldfa);
-
+		rules->policy.perms = kcalloc(2, sizeof(struct aa_perms),
+					      GFP_KERNEL);
+		if (!rules->policy.perms)
+			goto fail;
+		rules->policy.size = 2;
+	}
 	/* get file rules */
 	error = unpack_pdb(e, &rules->file, false, true, &info);
 	if (error) {
@@ -1001,9 +1006,22 @@ static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
 		   rules->policy.start[AA_CLASS_FILE]) {
 		rules->file.dfa = aa_get_dfa(rules->policy.dfa);
 		rules->file.start[AA_CLASS_FILE] = rules->policy.start[AA_CLASS_FILE];
-	} else
+		rules->file.perms = kcalloc(rules->policy.size,
+					    sizeof(struct aa_perms),
+					    GFP_KERNEL);
+		if (!rules->file.perms)
+			goto fail;
+		memcpy(rules->file.perms, rules->policy.perms,
+		       rules->policy.size * sizeof(struct aa_perms));
+		rules->file.size = rules->policy.size;
+	} else {
 		rules->file.dfa = aa_get_dfa(nulldfa);
-
+		rules->file.perms = kcalloc(2, sizeof(struct aa_perms),
+					    GFP_KERNEL);
+		if (!rules->file.perms)
+			goto fail;
+		rules->file.size = 2;
+	}
 	error = -EPROTO;
 	if (aa_unpack_nameX(e, AA_STRUCT, "data")) {
 		info = "out of memory";