# HG changeset patch
# User Ruslan Ermilov <ru@nginx.com>
# Date 1518207608 -10800
# Node ID 8b0553239592f5d0fd419e5116b9d343838685cf
# Parent  a49af443656f2b65ca5de9d8cad5594f44e18ff7
HTTP/2: fixed null pointer dereference with server push.

r->headers_in.host can be NULL in ngx_http_v2_push_resource().

This happens when a request is terminated with 400 before the :authority
or Host header is parsed, and either pushing is enabled on the server{}
level or error_page 400 redirects to a location with pushes configured.

Found by Coverity (CID 1429156).

diff --git a/src/http/v2/ngx_http_v2_filter_module.c b/src/http/v2/ngx_http_v2_filter_module.c
--- a/src/http/v2/ngx_http_v2_filter_module.c
+++ b/src/http/v2/ngx_http_v2_filter_module.c
@@ -946,7 +946,11 @@ ngx_http_v2_push_resource(ngx_http_reque
 
     host = r->headers_in.host;
 
-    if (authority->len == 0 && host) {
+    if (host == NULL) {
+        return NGX_ABORT;
+    }
+
+    if (authority->len == 0) {
 
         len = 1 + NGX_HTTP_V2_INT_OCTETS + host->value.len;