From 6c342ce2239c182c2428ce5a44cb32330434ae6e Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Fri, 11 Feb 2022 09:15:52 +0800 Subject: mctp: serial: Cancel pending work from ndo_uninit handler We cannot do the cancel_work_sync from after the unregister_netdev, as the dev pointer is no longer valid, causing a uaf on ldisc unregister (or device close). Instead, do the cancel_work_sync from the ndo_uninit op, where the dev still exists, but the queue has stopped. Fixes: 7bd9890f3d74 ("mctp: serial: cancel tx work on ldisc close") Reported-by: Luo Likang Tested-by: Luo Likang Signed-off-by: Jeremy Kerr Link: https://lore.kernel.org/r/20220211011552.1861886-1-jk@codeconstruct.com.au Signed-off-by: Jakub Kicinski --- drivers/net/mctp/mctp-serial.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/net/mctp/mctp-serial.c b/drivers/net/mctp/mctp-serial.c index eaa6fb3224bc..62723a7faa2d 100644 --- a/drivers/net/mctp/mctp-serial.c +++ b/drivers/net/mctp/mctp-serial.c @@ -403,8 +403,16 @@ static void mctp_serial_tty_receive_buf(struct tty_struct *tty, mctp_serial_push(dev, c[i]); } +static void mctp_serial_uninit(struct net_device *ndev) +{ + struct mctp_serial *dev = netdev_priv(ndev); + + cancel_work_sync(&dev->tx_work); +} + static const struct net_device_ops mctp_serial_netdev_ops = { .ndo_start_xmit = mctp_serial_tx, + .ndo_uninit = mctp_serial_uninit, }; static void mctp_serial_setup(struct net_device *ndev) @@ -483,7 +491,6 @@ static void mctp_serial_close(struct tty_struct *tty) int idx = dev->idx; unregister_netdev(dev->netdev); - cancel_work_sync(&dev->tx_work); ida_free(&mctp_serial_ida, idx); } -- cgit v1.2.3