Commit e3bfea23 authored Sep 18, 2013 by Peter Hurley Committed by Greg Kroah-Hartman Sep 25, 2013

tty: Prevent tty_port destruction if tty not released



If the tty driver mistakenly drops the last port reference
before the tty has been released, issue a diagnostic and
abort the port destruction.

This will leak memory and may zombify the port, but might
otherwise keep the machine in runnable state.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 103fcbe2

drivers/tty/tty_port.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -140,6 +140,10 @@ EXPORT_SYMBOL(tty_port_destroy);
		static void tty_port_destructor(struct kref *kref)
		{
		struct tty_port *port = container_of(kref, struct tty_port, kref);

		/* check if last port ref was dropped before tty release */
		if (WARN_ON(port->itty))
		return;
		if (port->xmit_buf)
		free_page((unsigned long)port->xmit_buf);
		tty_port_destroy(port);

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