Various fixes from emails Joachim Nilsson sent to tech@ many moons

ago. Sorry for the delay.

- Make sure we don't deref NULL ptr in skipwhite()
- Only deref vendp if not NULL
- Strings must be at least 2 chars for terminating NUL character

diff --git a/usr.bin/mg/interpreter.c b/usr.bin/mg/interpreter.c
index 6c954d3..6c33876 100644 (file)
--- a/usr.bin/mg/interpreter.c
+++ b/usr.bin/mg/interpreter.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: interpreter.c,v 1.5 2019/07/20 11:06:33 lum Exp $    */
+/*      $OpenBSD: interpreter.c,v 1.6 2021/02/24 14:17:18 lum Exp $    */
 /*
  * This file is in the public domain.
  *
@@ -138,7 +138,10 @@ multiarg(char *funstr)
                return (dobeep_msgs("Command takes no arguments: ", cmdp));
 
        /* now find the first argument */
-       p = fendp + 1;
+       if (fendp)
+               p = fendp + 1;
+       else
+               p = "";
        p = skipwhite(p);
        if (strlcpy(argbuf, p, sizeof(argbuf)) >= sizeof(argbuf))
                return (dobeep_msg("strlcpy error"));
@@ -268,7 +271,7 @@ static int
 foundlist(char *defstr)
 {
        struct varentry *vt, *v1 = NULL;
-       const char       e[1] = "e", t[1] = "t";
+       const char       e[2] = "e", t[2] = "t";
        char            *p, *vnamep, *vendp = NULL, *valp, *o;
        int              spc;
 
@@ -336,7 +339,9 @@ foundlist(char *defstr)
                        spc = 0;
                }
        }
-       *vendp = '\0';
+       if (vendp)
+               *vendp = '\0';
+
        if ((v1->vals = strndup(valp, BUFSIZE)) == NULL)
                return(dobeep_msg("strndup error"));