virtio: console: Fix crash when port is unplugged and blocked for write

When a program that has a virtio port opened and blocked for a write
operation, a port hot-unplug event will later led to a crash when
SIGTERM was sent to the program. Fix that.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index e3fb5296cf25..942a9826bd23 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -529,6 +529,10 @@ static bool will_write_block(struct port *port)
 {
         bool ret;
 
+        if (!port->guest_connected) {
+                /* Port got hot-unplugged. Let's exit. */
+                return false;
+        }
         if (!port->host_connected)
                 return true;