From: Lin Ma <linma@zju.edu.cn> stable inclusion from linux-4.19.194 commit 64700748e8a7af4883538c72ada57999d9a78e92 CVE: CVE-2021-3564 -------------------------------- 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> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- 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 e03faca84919e..fb47fe995cefd 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -1496,8 +1496,13 @@ 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); -- 2.25.1