From: Yang Yingliang yangyingliang@huawei.com

It is not allowed to call kfree_skb() from hardware interrupt context or with interrupts being disabled. The skb is unlinked from the queue, so it can be freed after spin_unlock_irqrestore().

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Signed-off-by: Yang Yingliang yangyingliang@huawei.com Acked-by: Oleksij Rempel o.rempel@pengutronix.de Link: https://lore.kernel.org/all/20221027091237.2290111-1-yangyingliang@huawei.co... Cc: stable@vger.kernel.org [mkl: adjust subject] Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- net/can/j1939/transport.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index d7d86c944d76..55f29c9f9e08 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -342,10 +342,12 @@ static void j1939_session_skb_drop_old(struct j1939_session *session) __skb_unlink(do_skb, &session->skb_queue); /* drop ref taken in j1939_session_skb_queue() */ skb_unref(do_skb); + spin_unlock_irqrestore(&session->skb_queue.lock, flags);

kfree_skb(do_skb); + } else { + spin_unlock_irqrestore(&session->skb_queue.lock, flags); } - spin_unlock_irqrestore(&session->skb_queue.lock, flags); }

void j1939_session_skb_queue(struct j1939_session *session,