Move valid domain name check into a new valid_domain() function.

Fix memory leak if getdomainname(2) fails and avoid using heap
garbage for the domain name matching in this case.

diff --git a/plugins/sudoers/match.c b/plugins/sudoers/match.c
index 97f538b0c44c05d4f58d0946460665259b9d3252..3fb36f5e4e5c1202f2433697b0ff4901070cd3ba 100644 (file)
--- a/plugins/sudoers/match.c
+++ b/plugins/sudoers/match.c
@@ -975,10 +975,30 @@ done:
     debug_return_bool(matched);
 }
 
+#if defined(HAVE_GETDOMAINNAME) || defined(SI_SRPC_DOMAIN)
+/*
+ * Check the domain for invalid characters.
+ * Linux getdomainname(2) returns (none) if no domain is set.
+ */
+static bool
+valid_domain(const char *domain)
+{
+    const char *cp;
+    debug_decl(valid_domain, SUDOERS_DEBUG_MATCH)
+
+    for (cp = domain; *cp != '\0'; cp++) {
+       /* Check for illegal characters, Linux may use "(none)". */
+       if (*cp == '(' || *cp == ')' || *cp == ',' || *cp == ' ')
+           break;
+    }
+    if (cp == domain || *cp != '\0')
+       debug_return_bool(false);
+    debug_return_bool(true);
+}
+
 /*
  * Get NIS-style domain name and copy from static storage or NULL if none.
  */
-#if defined(HAVE_GETDOMAINNAME) || defined(SI_SRPC_DOMAIN)
 const char *
 sudo_getdomainname(void)
 {
@@ -998,23 +1018,16 @@ sudo_getdomainname(void)
 
        domain = malloc(host_name_max + 1);
        if (domain != NULL) {
-# ifdef SI_SRPC_DOMAIN
            domain[0] = '\0';
+# ifdef SI_SRPC_DOMAIN
            rc = sysinfo(SI_SRPC_DOMAIN, domain, host_name_max + 1);
 # else
            rc = getdomainname(domain, host_name_max + 1);
 # endif
-           if (rc != -1 && domain[0] != '\0') {
-               const char *cp;
-
-               for (cp = domain; *cp != '\0'; cp++) {
-                   /* Check for illegal characters, Linux may use "(none)". */
-                   if (*cp == '(' || *cp == ')' || *cp == ',' || *cp == ' ') {
-                       free(domain);
-                       domain = NULL;
-                       break;
-                   }
-               }
+           if (rc == -1 || !valid_domain(domain)) {
+               /* Error or invalid domain name. */
+               free(domain);
+               domain = NULL;
            }
        } else {
            /* XXX - want to pass error back to caller */