# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1596679342 -10800
# Node ID 8253424d1aff6cbd2323670d3c4c20738c9e9fde
# Parent  da8d758aabebbba833405463aa5a785b4c324495
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
--- 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_h
     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);