From: Maxim Dounin <mdounin@mdounin.ru>
Date: Thu, 6 Aug 2020 02:02:22 +0000 (+0300)
Subject: Added size check to ngx_http_alloc_large_header_buffer().
X-Git-Tag: release-1.19.2~9
X-Git-Url: http://www.kaiwu.me/postgresql/commit/?a=commitdiff_plain;h=bd7dad5b0eb9f667a9c66ea5175a017ac51cd027;p=nginx.git

Added size check to ngx_http_alloc_large_header_buffer().

This ensures that copying won't write more than the buffer size
even if the buffer comes from hc->free and it is smaller than the large
client header buffer size in the virtual host configuration.  This might
happen if size of large client header buffers is different in name-based
virtual hosts, similarly to the problem with number of buffers fixed
in 6926:e662cbf1b932.
---

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 6feb6cc31..257c4064b 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -1647,6 +1647,12 @@ ngx_http_alloc_large_header_buffer(ngx_http_request_t *r,
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "http large header copy: %uz", r->header_in->pos - old);
 
+    if (r->header_in->pos - old > b->end - b->start) {
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                      "too large header to copy");
+        return NGX_ERROR;
+    }
+
     new = b->start;
 
     ngx_memcpy(new, old, r->header_in->pos - old);