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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Mattijs Korpershoek <mkorpershoek@baylibre.com>,
        Marcel Holtmann <marcel@holtmann.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 037/171] Bluetooth: hci_core: fix init for HCI_USER_CHANNEL
Date:   Thu,  2 Jan 2020 23:06:08 +0100
Message-Id: <20200102220552.181592808@linuxfoundation.org>
In-Reply-To: <20200102220546.960200039@linuxfoundation.org>
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From: Mattijs Korpershoek <mkorpershoek@baylibre.com>

[ Upstream commit eb8c101e28496888a0dcfe16ab86a1bee369e820 ]

During the setup() stage, HCI device drivers expect the chip to
acknowledge its setup() completion via vendor specific frames.

If userspace opens() such HCI device in HCI_USER_CHANNEL [1] mode,
the vendor specific frames are never tranmitted to the driver, as
they are filtered in hci_rx_work().

Allow HCI devices which operate in HCI_USER_CHANNEL mode to receive
frames if the HCI device is is HCI_INIT state.

[1] https://www.spinics.net/lists/linux-bluetooth/msg37345.html

Fixes: 23500189d7e0 ("Bluetooth: Introduce new HCI socket channel for user operation")
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bluetooth/hci_core.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 4bd72d2fe415..a70b078ceb3c 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -4180,7 +4180,14 @@ static void hci_rx_work(struct work_struct *work)
 			hci_send_to_sock(hdev, skb);
 		}
 
-		if (hci_dev_test_flag(hdev, HCI_USER_CHANNEL)) {
+		/* If the device has been opened in HCI_USER_CHANNEL,
+		 * the userspace has exclusive access to device.
+		 * When device is HCI_INIT, we still need to process
+		 * the data packets to the driver in order
+		 * to complete its setup().
+		 */
+		if (hci_dev_test_flag(hdev, HCI_USER_CHANNEL) &&
+		    !test_bit(HCI_INIT, &hdev->flags)) {
 			kfree_skb(skb);
 			continue;
 		}
-- 
2.20.1