From 3556fac71e41f342d61331f3367d48bbbc292308 Mon Sep 17 00:00:00 2001 From: Lin Ma Date: Tue, 25 May 2021 14:39:02 +0200 Subject: [PATCH] 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 Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: "David S. Miller" Cc: Jakub Kicinski Cc: linux-bluetooth@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lin Ma Signed-off-by: Hao Xiong Cc: stable Signed-off-by: Marcel Holtmann Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/hci_core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index b0d9c36acc033..4fad2ca661ed9 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -1608,8 +1608,13 @@ 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);