Received-SPF: pass (google.com: domain of linux-bluetooth-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Pavel Skripkin <paskripkin@gmail.com>
To:     marcel@holtmann.org, johan.hedberg@gmail.com
Cc:     linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
        Pavel Skripkin <paskripkin@gmail.com>, stable@vger.kernel.org,
        Rocky Liao <rjliao@codeaurora.org>
Subject: [PATCH v2] bluetooth: hci_qca: fix potential GPF
Date:   Mon,  3 May 2021 13:06:05 +0300
Message-Id: <20210503100605.5223-1-paskripkin@gmail.com>
In-Reply-To: <YI+s2Hms/56Pvatu@hovoldconsulting.com>
References: <YI+s2Hms/56Pvatu@hovoldconsulting.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

In qca_power_shutdown() qcadev local variable is
initialized by hu->serdev.dev private data, but
hu->serdev can be NULL and there is a check for it.

Since, qcadev is not used before

	if (!hu->serdev)
		return;

we can move its initialization after this "if" to
prevent GPF.

Fixes: 5559904ccc08 ("Bluetooth: hci_qca: Add QCA Rome power off support to the qca_power_shutdown()")
Cc: stable@vger.kernel.org # v5.6+
Cc: Rocky Liao <rjliao@codeaurora.org>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 drivers/bluetooth/hci_qca.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index de36af63e182..9589ef6c0c26 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -1820,8 +1820,6 @@ static void qca_power_shutdown(struct hci_uart *hu)
 	unsigned long flags;
 	enum qca_btsoc_type soc_type = qca_soc_type(hu);
 
-	qcadev = serdev_device_get_drvdata(hu->serdev);
-
 	/* From this point we go into power off state. But serial port is
 	 * still open, stop queueing the IBS data and flush all the buffered
 	 * data in skb's.
@@ -1837,6 +1835,8 @@ static void qca_power_shutdown(struct hci_uart *hu)
 	if (!hu->serdev)
 		return;
 
+	qcadev = serdev_device_get_drvdata(hu->serdev);
+
 	if (qca_is_wcn399x(soc_type)) {
 		host_set_baudrate(hu, 2400);
 		qca_send_power_pulse(hu, false);
-- 
2.31.1