From: Zhang Changzhong zhangchangzhong@huawei.com

According to SAE-J1939-21, the data length of TP.DT must be 8 bytes, so cancel session when receive unexpected TP.DT message.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Link: https://lore.kernel.org/all/1632972800-45091-1-git-send-email-zhangchangzhon... Cc: stable@vger.kernel.org Signed-off-by: Zhang Changzhong zhangchangzhong@huawei.com Acked-by: Oleksij Rempel o.rempel@pengutronix.de Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- net/can/j1939/transport.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index bfb0718d4587..1ea6fee3d986 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -1788,6 +1788,7 @@ static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb, static void j1939_xtp_rx_dat_one(struct j1939_session *session, struct sk_buff *skb) { + enum j1939_xtp_abort abort = J1939_XTP_ABORT_FAULT; struct j1939_priv *priv = session->priv; struct j1939_sk_buff_cb *skcb, *se_skcb; struct sk_buff *se_skb = NULL; @@ -1802,9 +1803,11 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session,

skcb = j1939_skb_to_cb(skb); dat = skb->data; - if (skb->len <= 1) + if (skb->len != 8) { /* makes no sense */ + abort = J1939_XTP_ABORT_UNEXPECTED_DATA; goto out_session_cancel; + }

switch (session->last_cmd) { case 0xff: @@ -1903,7 +1906,7 @@ static void j1939_xtp_rx_dat_one(struct j1939_session *session, out_session_cancel: kfree_skb(se_skb); j1939_session_timers_cancel(session); - j1939_session_cancel(session, J1939_XTP_ABORT_FAULT); + j1939_session_cancel(session, abort); j1939_session_put(session); }