From: Johan Hovold <johan@xxxxxxxxxx> commit 65c001df517a7bf9be8621b53d43c89f426ce8d6 upstream. Make sure to set the tty class-device driver data before registering the tty to avoid having a racing open() dereference a NULL pointer. Fixes: 9c1d784afc6f ("Staging: ipack/devices/ipoctal: Get rid of ipoctal_list.") Cc: stable@xxxxxxxxxxxxxxx # 3.7 Acked-by: Samuel Iglesias Gonsalvez <siglesias@xxxxxxxxxx> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210917114622.5412-3-johan@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/ipack/devices/ipoctal.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/ipack/devices/ipoctal.c +++ b/drivers/ipack/devices/ipoctal.c @@ -393,13 +393,13 @@ static int ipoctal_inst_slot(struct ipoc spin_lock_init(&channel->lock); channel->pointer_read = 0; channel->pointer_write = 0; - tty_dev = tty_port_register_device(&channel->tty_port, tty, i, NULL); + tty_dev = tty_port_register_device_attr(&channel->tty_port, tty, + i, NULL, channel, NULL); if (IS_ERR(tty_dev)) { dev_err(&ipoctal->dev->dev, "Failed to register tty device.\n"); tty_port_destroy(&channel->tty_port); continue; } - dev_set_drvdata(tty_dev, channel); } /*