Commit 054b0b4f authored May 25, 2021 by Lin Ma Committed by Greg Kroah-Hartman Jun 10, 2021

Bluetooth: fix the erroneous flush_work() order



commit 6a137caec23aeb9e036cdfd8a46dd8a366460e5d upstream.

In the cleanup routine for failed initialization of HCI device,
the flush_work(&hdev->rx_work) need to be finished before the
flush_work(&hdev->cmd_work). Otherwise, the hci_rx_work() can
possibly invoke new cmd_work and cause a bug, like double free,
in late processings.

This was assigned CVE-2021-3564.

This patch reorder the flush_work() to fix this bug.

Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: linux-bluetooth@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Signed-off-by: Hao Xiong <mart1n@zju.edu.cn>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 079af8d9

net/bluetooth/hci_core.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1555,8 +1555,13 @@ static int hci_dev_do_open(struct hci_dev *hdev)
		} else {
		/* Init failed, cleanup */
		flush_work(&hdev->tx_work);
		flush_work(&hdev->cmd_work);

		/* Since hci_rx_work() is possible to awake new cmd_work
		* it should be flushed first to avoid unexpected call of
		* hci_cmd_work()
		*/
		flush_work(&hdev->rx_work);
		flush_work(&hdev->cmd_work);

		skb_queue_purge(&hdev->cmd_q);
		skb_queue_purge(&hdev->rx_q);