Merge pull request #537 from stoeckmann/vsnprintf

Handle vsnprintf corner cases.
akheron · May 23, 2020 · 52dfc3d · 52dfc3d
2 parents e9ebfa7 + 38b001e
commit 52dfc3d
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/src/value.c b/src/value.c
@@ -797,16 +797,18 @@ json_t *json_vsprintf(const char *fmt, va_list ap) {
     va_copy(aq, ap);
 
     length = vsnprintf(NULL, 0, fmt, ap);
+    if (length < 0)
+        goto out;
     if (length == 0) {
         json = json_string("");
         goto out;
     }
 
-    buf = jsonp_malloc(length + 1);
+    buf = jsonp_malloc((size_t)length + 1);
     if (!buf)
         goto out;
 
-    vsnprintf(buf, length + 1, fmt, aq);
+    vsnprintf(buf, (size_t)length + 1, fmt, aq);
     if (!utf8_check_string(buf, length)) {
         jsonp_free(buf);
         goto out;