Re: [PATCH] Bluetooth: hci_qca: Fix crash with non-serdev devices

From: Balakrishna Godavarthi
Date: Mon Apr 01 2019 - 03:42:15 EST


On 2019-03-14 05:22, Matthias Kaehlcke wrote:
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@xxxxxxxxxxxxxx>
Reported-by: Rocky Liao <rjliao@xxxxxxxxxxxxxx>
Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
---
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 */

Reviewed-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>

--
Regards
Balakrishna.