channels: Set error state when closed channel is read

When an attempt to read a closed channel happens, set the session error
state properly.

Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

src/channels.c

@@ -2766,8 +2766,13 @@ int ssh_channel_read_timeout(ssh_channel channel,
   /*
    * If the channel is closed or in an error state, reading from it is an error
    */
-  if (session->session_state == SSH_SESSION_STATE_ERROR ||
-      channel->state == SSH_CHANNEL_STATE_CLOSED) {
+  if (session->session_state == SSH_SESSION_STATE_ERROR) {
+      return SSH_ERROR;
+  }
+  if (channel->state == SSH_CHANNEL_STATE_CLOSED) {
+      ssh_set_error(session,
+                    SSH_FATAL,
+                    "Remote channel is closed.");
       return SSH_ERROR;
   }
   if (channel->remote_eof && ssh_buffer_get_len(stdbuf) == 0) {