tty: Allow uart_register/unregister/register
This is legitimate but because we don't clear the drv->state pointer in the
unregister code causes a bogus BUG().
Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=42880
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 59fb3ba..a21dc8e 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2282,6 +2282,7 @@
tty_unregister_driver(p);
put_tty_driver(p);
kfree(drv->state);
+ drv->state = NULL;
drv->tty_driver = NULL;
}