From: Roman Arutyunyan <arut@nginx.com>
Date: Mon, 27 Apr 2026 05:40:16 +0000 (+0400)
Subject: Mp4: avoid adding or comparing to null pointer
X-Git-Tag: release-1.31.1~6
X-Git-Url: http://git.kaiwu.me/sitemap.xml?a=commitdiff_plain;h=18a70a4d5806b5578d00460493954262ece55019;p=nginx.git

Mp4: avoid adding or comparing to null pointer

It is considered undefined behavior.

Reported by Geonwoo.kim (awo@kakao.com).
---

diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c
index 678d6296c..0ccdf135a 100644
--- a/src/http/modules/ngx_http_mp4_module.c
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -1063,7 +1063,9 @@ ngx_http_mp4_read(ngx_http_mp4_file_t *mp4, size_t size)
 {
     ssize_t  n;
 
-    if (mp4->buffer_pos + size <= mp4->buffer_end) {
+    if (mp4->buffer_pos && mp4->buffer_end
+        && mp4->buffer_pos + size <= mp4->buffer_end)
+    {
         return NGX_OK;
     }