net: hso: fix NULL-deref on disconnect regression
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>
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 38f3915..02de948 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -3105,7 +3105,7 @@
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);
}
}
