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From:   Matthias Kaehlcke <mka@chromium.org>
MIME-Version: 1.0
Date:   Wed, 13 Mar 2019 16:52:19 -0700
Message-ID: <CAG5bF+TCPc=m_O33RHXHrt34T1Dz1zHLSkXfpxAoOTmrffGJ7w@mail.gmail.com>
Subject: [PATCH] Bluetooth: hci_qca: Fix crash with non-serdev devices
To:     Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>
Cc:     linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
        Balakrishna Godavarthi <bgodavar@codeaurora.org>,
        Hemantg <hemantg@codeaurora.org>,
        Rocky Liao <rjliao@codeaurora.org>,
        Matthias Kaehlcke <mka@chromium.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

qca_set_baudrate() calls serdev_device_wait_until_sent() assuming that
the HCI is always associated with a serdev device. This isn't true for
ROME controllers instantiated through ldisc, where the call causes a
crash due to a NULL pointer dereferentiation. Only call the function
when we have a serdev device. The timeout for ROME devices at the end
of qca_set_baudrate() is long enough to be reasonably sure that the
command was sent.

Fixes: fa9ad876b8e0 ("Bluetooth: hci_qca: Add support for Qualcomm
Bluetooth chip wcn3990")
Reported-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
Reported-by: Rocky Liao <rjliao@codeaurora.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
 drivers/bluetooth/hci_qca.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 4ea995d610d2..714a6a16f9d5 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -1004,7 +1004,8 @@ static int qca_set_baudrate(struct hci_dev
*hdev, uint8_t baudrate)
 	while (!skb_queue_empty(&qca->txq))
 		usleep_range(100, 200);

-	serdev_device_wait_until_sent(hu->serdev,
+	if (hu->serdev)
+		serdev_device_wait_until_sent(hu->serdev,
 		      msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS));

 	/* Give the controller time to process the request */
-- 
2.21.0.360.g471c308f928-goog