| From 2bf2744cef70a672fa78f69f91e8b9c2f5037fc3 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 29 May 2020 12:59:48 +0300 |
| Subject: Bluetooth: hci_qca: Fix an error pointer dereference |
| |
| From: Dan Carpenter <dan.carpenter@oracle.com> |
| |
| [ Upstream commit 4c07a5d7aeb39f559b29aa58ec9a8a5ab4282cb0 ] |
| |
| When a function like devm_clk_get_optional() function returns both error |
| pointers on error and NULL then the NULL return means that the optional |
| feature is deliberately disabled. It is a special sort of success and |
| should not trigger an error message. The surrounding code should be |
| written to check for NULL and not crash. |
| |
| On the other hand, if we encounter an error, then the probe from should |
| clean up and return a failure. |
| |
| In this code, if devm_clk_get_optional() returns an error pointer then |
| the kernel will crash inside the call to: |
| |
| clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ); |
| |
| The error handling must be updated to prevent that. |
| |
| Fixes: 77131dfec6af ("Bluetooth: hci_qca: Replace devm_gpiod_get() with devm_gpiod_get_optional()") |
| Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> |
| Signed-off-by: Marcel Holtmann <marcel@holtmann.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/bluetooth/hci_qca.c | 18 +++++++++--------- |
| 1 file changed, 9 insertions(+), 9 deletions(-) |
| |
| diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c |
| index 14e4d2eaf8959..568f7ec20b000 100644 |
| --- a/drivers/bluetooth/hci_qca.c |
| +++ b/drivers/bluetooth/hci_qca.c |
| @@ -1941,17 +1941,17 @@ static int qca_serdev_probe(struct serdev_device *serdev) |
| } |
| |
| qcadev->susclk = devm_clk_get_optional(&serdev->dev, NULL); |
| - if (!qcadev->susclk) { |
| + if (IS_ERR(qcadev->susclk)) { |
| dev_warn(&serdev->dev, "failed to acquire clk\n"); |
| - } else { |
| - err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ); |
| - if (err) |
| - return err; |
| - |
| - err = clk_prepare_enable(qcadev->susclk); |
| - if (err) |
| - return err; |
| + return PTR_ERR(qcadev->susclk); |
| } |
| + err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ); |
| + if (err) |
| + return err; |
| + |
| + err = clk_prepare_enable(qcadev->susclk); |
| + if (err) |
| + return err; |
| |
| err = hci_uart_register_device(&qcadev->serdev_hu, &qca_proto); |
| if (err) { |
| -- |
| 2.25.1 |
| |