[PATCH 5.7 080/124] can: j1939: abort multipacket broadcast session when timeout occurs

[Greg Kroah-Hartman]

From: Zhang Changzhong <zhangchangzhong@xxxxxxxxxx>

[ Upstream commit 2b8b2e31555cf55ba3680fb28e2b382e168d7ea1 ]

If timeout occurs, j1939_tp_rxtimer() first calls hrtimer_start() to restart
rxtimer, and then calls __j1939_session_cancel() to set session->state =
J1939_SESSION_WAITING_ABORT. At next timeout expiration, because of the
J1939_SESSION_WAITING_ABORT session state j1939_tp_rxtimer() will call
j1939_session_deactivate_activate_next() to deactivate current session, and
rxtimer won't be set.

But for multipacket broadcast session, __j1939_session_cancel() don't set
session->state = J1939_SESSION_WAITING_ABORT, thus current session won't be
deactivate and hrtimer_start() is called to start new rxtimer again and again.

So fix it by moving session->state = J1939_SESSION_WAITING_ABORT out of if
(!j1939_cb_is_broadcast(&session->skcb)) statement.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <zhangchangzhong@xxxxxxxxxx>
Link: https://lore.kernel.org/r/1596599425-5534-4-git-send-email-zhangchangzhong@xxxxxxxxxx
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/can/j1939/transport.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index d1a9adde677b0..e3167619b196f 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1074,9 +1074,9 @@ static void __j1939_session_cancel(struct j1939_session *session,
 	lockdep_assert_held(&session->priv->active_session_list_lock);
 
 	session->err = j1939_xtp_abort_to_errno(priv, err);
+	session->state = J1939_SESSION_WAITING_ABORT;
 	/* do not send aborts on incoming broadcasts */
 	if (!j1939_cb_is_broadcast(&session->skcb)) {
-		session->state = J1939_SESSION_WAITING_ABORT;
 		j1939_xtp_tx_abort(priv, &session->skcb,
 				   !session->transmission,
 				   err, session->skcb.addr.pgn);
-- 
2.25.1