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 6feb6cc31c30a4c91c0f4bd4290529980092702f..257c4064b3a935c7d1fe9908faee230660ac54e4 100644 (file)
--- 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);