When performing warm boot tests with an MT7920 device, we encounter
NULL pointer dereferences with failure rate 5/30. The crash occurs
during device suspend when btusb attempts to access data->hdev where
data is NULL. This may happen due to a race condition between PM suspend
and device disconnect. The root cause needs further investigation.
BUG: kernel NULL pointer dereference, address: 0000000000000000
Workqueue: pm pm_runtime_work
RIP: 0010:btusb_suspend+0x1d/0x1d0 [btusb]
Add a NULL check for data and return -ENODEV in this case to prevent
the NULL pointer dereference. This indicates that the device is no
longer available, which is appropriate when the driver's private data
is missing.
Signed-off-by: En-Wei Wu <en-wei.wu@xxxxxxxxxxxxx>
---
Changes in v2:
- Change "dereference" to "dereferences" in commit message
- Re-flow commit message lines to use more characters per line
drivers/bluetooth/btusb.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 279fe6c115fa..a0461528548b 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -4096,6 +4096,9 @@ static int btusb_suspend(struct usb_interface *intf, pm_message_t message)
BT_DBG("intf %p", intf);
+ if (!data)
+ return -ENODEV;
+
/* Don't auto-suspend if there are connections; external suspend calls
* shall never fail.
*/
--
2.43.0
