Commit fea7b02f authored Feb 28, 2013 by Dean Jenkins Committed by Gustavo Padovan Mar 08, 2013

Bluetooth: Avoid rfcomm_session_timeout using freed session



Use del_timer_sync() instead of del_timer() as this ensures
that rfcomm_session_timeout() is not running on a different
CPU when rfcomm_session_put() is called. This avoids a race
condition on SMP systems because potentially
rfcomm_session_timeout() could reuse the freed RFCOMM session
structure caused by the execution of rfcomm_session_put().

Note that this modification makes the reason for the RFCOMM
session refcnt mechanism redundant.

Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

parent be9f97f0

net/bluetooth/rfcomm/core.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -257,7 +257,7 @@ static void rfcomm_session_clear_timer(struct rfcomm_session *s)
	{		{
	BT_DBG("session %p state %ld", s, s->state);		BT_DBG("session %p state %ld", s, s->state);

	if (del_timer(&s->timer))		if (del_timer_sync(&s->timer))
	rfcomm_session_put(s);		rfcomm_session_put(s);
	}		}