The driver shutdown callback (which sends EDL_SOC_RESET to the device
over serdev) should not be invoked when HCI device is not open (e.g. if
hci_dev_open_sync() failed), because the serdev and its TTY are not open
either. Also skip this step if device is powered off
(qca_power_shutdown()).
The shutdown callback causes use-after-free during system reboot with
Qualcomm Atheros Bluetooth:
Unable to handle kernel paging request at virtual address 0072662f67726fd7
...
CPU: 6 PID: 1 Comm: systemd-shutdow Tainted: G W 6.1.0-rt5-00325-g8a5f56bcfcca #8
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Call trace:
tty_driver_flush_buffer+0x4/0x30
serdev_device_write_flush+0x24/0x34
qca_serdev_shutdown+0x80/0x130 [hci_uart]
device_shutdown+0x15c/0x260
kernel_restart+0x48/0xac
KASAN report:
BUG: KASAN: use-after-free in tty_driver_flush_buffer+0x1c/0x50
Read of size 8 at addr ffff16270c2e0018 by task systemd-shutdow/1
CPU: 7 PID: 1 Comm: systemd-shutdow Not tainted 6.1.0-next-20221220-00014-gb85aaf97fb01-dirty #28
Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
Call trace:
dump_backtrace.part.0+0xdc/0xf0
show_stack+0x18/0x30
dump_stack_lvl+0x68/0x84
print_report+0x188/0x488
kasan_report+0xa4/0xf0
__asan_load8+0x80/0xac
tty_driver_flush_buffer+0x1c/0x50
ttyport_write_flush+0x34/0x44
serdev_device_write_flush+0x48/0x60
qca_serdev_shutdown+0x124/0x274
device_shutdown+0x1e8/0x350
kernel_restart+0x48/0xb0
__do_sys_reboot+0x244/0x2d0
__arm64_sys_reboot+0x54/0x70
invoke_syscall+0x60/0x190
el0_svc_common.constprop.0+0x7c/0x160
do_el0_svc+0x44/0xf0
el0_svc+0x2c/0x6c
el0t_64_sync_handler+0xbc/0x140
el0t_64_sync+0x190/0x194
Fixes: 7e7bbddd029b ("Bluetooth: hci_qca: Fix qca6390 enable failure after warm reboot")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
---
Changes since v1:
1. Drop serdev patch and fix it only on BT side.
2. Update commit msg.
---
drivers/bluetooth/hci_qca.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index bb7623fe53a8..157fc4d024c1 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -2166,10 +2166,16 @@ static void qca_serdev_shutdown(struct device *dev)
int timeout = msecs_to_jiffies(CMD_TRANS_TIMEOUT_MS);
struct serdev_device *serdev = to_serdev_device(dev);
struct qca_serdev *qcadev = serdev_device_get_drvdata(serdev);
+ struct hci_uart *hu = &qcadev->serdev_hu;
+ struct hci_dev *hdev = hu->hdev;
+ struct qca_data *qca = hu->priv;
const u8 ibs_wake_cmd[] = { 0xFD };
const u8 edl_reset_soc_cmd[] = { 0x01, 0x00, 0xFC, 0x01, 0x05 };
if (qcadev->btsoc_type == QCA_QCA6390) {
+ if (test_bit(QCA_BT_OFF, &qca->flags) || !test_bit(HCI_RUNNING, &hdev->flags))
+ return;
+
serdev_device_write_flush(serdev);
ret = serdev_device_write_buf(serdev, ibs_wake_cmd,
sizeof(ibs_wake_cmd));
--
2.34.1
