tls,http2: handle writes after SSL destroy more gracefully

addaleax · MylesBorins · commit f5985c734cf1 · 2018-09-25T16:46:56.000-04:00
This might otherwise result in a hard crash when trying to write to a socket after a sudden disconnect. Note that the test here uses an aborted `h2load` run to create the failing requests; That’s far from ideal, but it provides a reasonably reliably reproduction at this point. Backport-PR-URL: #22924 PR-URL: #18987 Fixes: #18973 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
diff --git a/src/tls_wrap.cc b/src/tls_wrap.cc
@@ -601,7 +601,12 @@ int TLSWrap::DoWrite(WriteWrap* w,
                      size_t count,
                      uv_stream_t* send_handle) {
   CHECK_EQ(send_handle, nullptr);
-  CHECK_NE(ssl_, nullptr);
+
+  if (ssl_ == nullptr) {
+    ClearError();
+    error_ = "Write after DestroySSL";
+    return UV_EPROTO;
+  }
 
   bool empty = true;
 
@@ -642,12 +647,6 @@ int TLSWrap::DoWrite(WriteWrap* w,
     return 0;
   }
 
-  if (ssl_ == nullptr) {
-    ClearError();
-    error_ = "Write after DestroySSL";
-    return UV_EPROTO;
-  }
-
   crypto::MarkPopErrorOnReturn mark_pop_error_on_return;
 
   int written = 0;
