# HG changeset patch
# User Roman Arutyunyan <arut@nginx.com>
# Date 1653567476 -14400
# Node ID 5b1011b5702b5c5db2ba3d392a4da25596183cc2
# Parent  c2f5d79cde64457f1fa7344c56a5248a677a7e46
HTTP/3: require that field section base index is not negative.

RFC 9204 explicitly requires that.

diff --git a/src/http/v3/ngx_http_v3_parse.c b/src/http/v3/ngx_http_v3_parse.c
--- a/src/http/v3/ngx_http_v3_parse.c
+++ b/src/http/v3/ngx_http_v3_parse.c
@@ -474,7 +474,13 @@ done:
     }
 
     if (st->sign) {
+        if (st->insert_count <= st->delta_base) {
+            ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent negative base");
+            return NGX_HTTP_V3_ERR_DECOMPRESSION_FAILED;
+        }
+
         st->base = st->insert_count - st->delta_base - 1;
+
     } else {
         st->base = st->insert_count + st->delta_base;
     }