print: fix global-buffer-overflow in print module

zpl-c · Sep 11, 2022 · 671f30d · 671f30d
1 parent fe64cd4
commit 671f30d
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Showing 2 changed files with 4 additions and 1 deletion.
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,4 +1,5 @@
-18.0.1  - Fix ADT parser wrongly assuming that an IP address is a real number.
+18.0.2  - fix global-buffer-overflow in print module
+18.0.1  - fix ADT parser wrongly assuming that an IP address is a real number
 18.0.0  - removed coroutines module
         - removed timer module
         - rename zpl_adt_get -> zpl_adt_query

diff --git a/code/source/core/print.c b/code/source/core/print.c
@@ -143,6 +143,7 @@ zpl_internal zpl_isize zpl__print_string(char *text, zpl_isize max_len, zpl__for
 
     if (info && (info->width == 0 || info->flags & ZPL_FMT_MINUS)) {
         if (info->precision > 0) len = info->precision < len ? info->precision : len;
+        if (res+len > max_len) return res;
         res += zpl_strlcpy(text, str, len);
         text += res;
 
@@ -159,6 +160,7 @@ zpl_internal zpl_isize zpl__print_string(char *text, zpl_isize max_len, zpl__for
             while (padding-- > 0 && remaining-- > 0) *text++ = pad, res++;
         }
 
+        if (res+len > max_len) return res;
         res += zpl_strlcpy(text, str, len);
     }