auth:kerberos: Fix resource leak in parse_principal()

Reported by Red Hat internal covscan
leaked_storage: Variable "princ" going out of scope leaks the storage it points to.

Signed-off-by: Pavel Filipenský <pfilipensky@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

diff --git a/source4/auth/kerberos/kerberos_util.c b/source4/auth/kerberos/kerberos_util.c
index ec164aaedad3961723f9260f156141341221a691..432266aab91d131c30609ede3a10f21f76fde3c4 100644 (file)
--- a/source4/auth/kerberos/kerberos_util.c
+++ b/source4/auth/kerberos/kerberos_util.c
@@ -56,6 +56,24 @@ static krb5_error_code parse_principal(TALLOC_CTX *parent_ctx,
                 return 0;
        }
 
+       /*
+        * Start with talloc(), talloc_reference() and only then call
+        * krb5_parse_name(). If any of them fails, the cleanup code is simpler.
+        */
+       mem_ctx = talloc(parent_ctx, struct principal_container);
+       if (!mem_ctx) {
+               (*error_string) = error_message(ENOMEM);
+               return ENOMEM;
+       }
+
+       mem_ctx->smb_krb5_context = talloc_reference(mem_ctx,
+                                                    smb_krb5_context);
+       if (mem_ctx->smb_krb5_context == NULL) {
+               (*error_string) = error_message(ENOMEM);
+               talloc_free(mem_ctx);
+               return ENOMEM;
+       }
+
        ret = krb5_parse_name(smb_krb5_context->krb5_context,
                              princ_string, princ);
 
@@ -63,19 +81,12 @@ static krb5_error_code parse_principal(TALLOC_CTX *parent_ctx,
                (*error_string) = smb_get_krb5_error_message(
                                                smb_krb5_context->krb5_context,
                                                ret, parent_ctx);
+               talloc_free(mem_ctx);
                return ret;
        }
 
-       mem_ctx = talloc(parent_ctx, struct principal_container);
-       if (!mem_ctx) {
-               (*error_string) = error_message(ENOMEM);
-               return ENOMEM;
-       }
-
        /* This song-and-dance effectivly puts the principal
         * into talloc, so we can't loose it. */
-       mem_ctx->smb_krb5_context = talloc_reference(mem_ctx,
-                                                    smb_krb5_context);
        mem_ctx->principal = *princ;
        talloc_set_destructor(mem_ctx, free_principal);
        return 0;