From: Johan Hovold <johan@kernel.org> commit 2ad5692db72874f02b9ad551d26345437ea4f7f3 upstream. Commit 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration") fixed the racy minor allocation reported by syzbot, but introduced an unconditional NULL-pointer dereference on every disconnect instead. Specifically, the serial device table must no longer be accessed after the minor has been released by hso_serial_tty_unregister(). Fixes: 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration") Cc: stable@vger.kernel.org Cc: Anirudh Rayabharam <mail@anirudhrb.com> Reported-by: Leonardo Antoniazzi <leoanto@aruba.it> Signed-off-by: Johan Hovold <johan@kernel.org> Reviewed-by: Anirudh Rayabharam <mail@anirudhrb.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/net/usb/hso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index 2eb33d2bb7ad4..94f1c2422f844 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -3114,7 +3114,7 @@ static void hso_free_interface(struct usb_interface *interface) cancel_work_sync(&serial_table[i]->async_put_intf); cancel_work_sync(&serial_table[i]->async_get_intf); hso_serial_tty_unregister(serial); - kref_put(&serial_table[i]->ref, hso_serial_ref_free); + kref_put(&serial->parent->ref, hso_serial_ref_free); } } -- 2.25.1