git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From c3c06c61890da80494bb196f75d89b791adda87f Mon Sep 17 00:00:00 2001
   2 From: Yang Yingliang <yangyingliang@huawei.com>
   3 Date: Thu, 27 Oct 2022 17:12:37 +0800
   4 Subject: can: j1939: transport: j1939_session_skb_drop_old(): spin_unlock_irqrestore() before kfree_skb()
   5
   6 From: Yang Yingliang <yangyingliang@huawei.com>
   7
   8 commit c3c06c61890da80494bb196f75d89b791adda87f upstream.
   9
  10 It is not allowed to call kfree_skb() from hardware interrupt context
  11 or with interrupts being disabled. The skb is unlinked from the queue,
  12 so it can be freed after spin_unlock_irqrestore().
  13
  14 Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
  15 Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
  16 Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
  17 Link: https://lore.kernel.org/all/20221027091237.2290111-1-yangyingliang@huawei.com
  18 Cc: stable@vger.kernel.org
  19 [mkl: adjust subject]
  20 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22 ---
  23  net/can/j1939/transport.c |    4 +++-
  24  1 file changed, 3 insertions(+), 1 deletion(-)
  25
  26 --- a/net/can/j1939/transport.c
  27 +++ b/net/can/j1939/transport.c
  28 @@ -342,10 +342,12 @@ static void j1939_session_skb_drop_old(s
  29                 __skb_unlink(do_skb, &session->skb_queue);
  30                 /* drop ref taken in j1939_session_skb_queue() */
  31                 skb_unref(do_skb);
  32 +               spin_unlock_irqrestore(&session->skb_queue.lock, flags);
  33
  34                 kfree_skb(do_skb);
  35 +       } else {
  36 +               spin_unlock_irqrestore(&session->skb_queue.lock, flags);
  37         }
  38 -       spin_unlock_irqrestore(&session->skb_queue.lock, flags);
  39  }
  40
  41  void j1939_session_skb_queue(struct j1939_session *session,