From 9b7ee09abfd426b99aa1ea81d19a3b2818eeabf9 Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@gmail.com>
Date: Sun, 22 Oct 2017 21:42:59 +0300
Subject: [PATCH] prepoc: Fix heap-buffer-overflow in detoken

Just make sure we've a data to process.

https://bugzilla.nasm.us/show_bug.cgi?id=3392424

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
 asm/preproc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/asm/preproc.c b/asm/preproc.c
index 9642edcb..475926d8 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -1254,7 +1254,8 @@ static char *detoken(Token * tlist, bool expand_locals)
     int len = 0;
 
     list_for_each(t, tlist) {
-        if (t->type == TOK_PREPROC_ID && t->text[1] == '!') {
+        if (t->type == TOK_PREPROC_ID && t->text &&
+            t->text[0] && t->text[1] == '!') {
             char *v;
             char *q = t->text;
 
-- 
2.11.4.GIT