From: Peter Hurley Date: Mon, 10 Feb 2014 01:59:09 +0000 (-0500) Subject: Bluetooth: Fix RFCOMM tty teardown race X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c949c224cfd7d5445ef947e8b93c0657323d5be5;p=linux-beck.git Bluetooth: Fix RFCOMM tty teardown race RFCOMM tty device teardown can race with new tty device registration for the same device id: CPU 0 | CPU 1 rfcomm_dev_add | rfcomm_dev_destruct | spin_lock | list_del <== dev_id no longer used | spin_unlock spin_lock | . [search rfcomm_dev_list] | . [dev_id not in use] | . [initialize new rfcomm_dev] | . spin_unlock | . | . tty_port_register_device | tty_unregister_device Don't remove rfcomm_dev from the device list until after tty device unregistration has completed. Signed-off-by: Peter Hurley Tested-By: Alexander Holler Signed-off-by: Marcel Holtmann --- diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c index bb570d95adca..6ea08b05b53a 100644 --- a/net/bluetooth/rfcomm/tty.c +++ b/net/bluetooth/rfcomm/tty.c @@ -84,10 +84,6 @@ static void rfcomm_dev_destruct(struct tty_port *port) BT_DBG("dev %p dlc %p", dev, dlc); - spin_lock(&rfcomm_dev_lock); - list_del(&dev->list); - spin_unlock(&rfcomm_dev_lock); - rfcomm_dlc_lock(dlc); /* Detach DLC if it's owned by this dev */ if (dlc->owner == dev) @@ -98,6 +94,10 @@ static void rfcomm_dev_destruct(struct tty_port *port) tty_unregister_device(rfcomm_tty_driver, dev->id); + spin_lock(&rfcomm_dev_lock); + list_del(&dev->list); + spin_unlock(&rfcomm_dev_lock); + kfree(dev); /* It's safe to call module_put() here because socket still