term: fix read on a closed PTY

* term/ptyio.c (pty_io_read): Return EIO if the terminal has been closed.

1 files changed, 6 insertions, 0 deletions

diff --git a/term/ptyio.c b/term/ptyio.c
index 44a215bb..2da7d6c8 100644
--- a/term/ptyio.c
+++ b/term/ptyio.c
@@ -331,6 +331,12 @@ pty_io_read (struct trivfs_protid *cred,
 	}
     }
 
+  if (!(termflags & TTY_OPEN))
+    {
+      pthread_mutex_unlock (&global_lock);
+      return EIO;
+    }
+
   if (control_byte)
     {
       size = 1;