fix an accidental NULL deref introduced last year, found by patrick.

rewrite the code with a goto so this never happens again.
ok patrick millert

diff --git a/libexec/login_passwd/login_passwd.c b/libexec/login_passwd/login_passwd.c
index df83a82..8e5fe2b 100644 (file)
--- a/libexec/login_passwd/login_passwd.c
+++ b/libexec/login_passwd/login_passwd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: login_passwd.c,v 1.19 2021/01/02 20:32:20 millert Exp $       */
+/*     $OpenBSD: login_passwd.c,v 1.20 2021/11/16 21:55:21 deraadt Exp $       */
 
 /*-
  * Copyright (c) 1995 Berkeley Software Design, Inc. All rights reserved.
@@ -121,8 +121,7 @@ main(int argc, char *argv[])
        if (wheel != NULL && strcmp(wheel, "yes") != 0) {
                fprintf(back, BI_VALUE " errormsg %s\n",
                    "you are not in group wheel");
-               fprintf(back, BI_REJECT "\n");
-               exit(1);
+               goto reject;
        }
 
        if (mode == 1) {
@@ -151,7 +150,7 @@ main(int argc, char *argv[])
                        pass = readpassphrase("Password:", pbuf, sizeof(pbuf),
                            RPP_ECHO_OFF);
                        if (pass == NULL)
-                               fprintf(back, BI_REJECT "\n");
+                               goto reject;
                }
        }
 
@@ -168,6 +167,7 @@ main(int argc, char *argv[])
                    exit(0);
                }
        }
+reject:
        fprintf(back, BI_REJECT "\n");
        exit(1);
 }