Executive brief
The Bitland MIFS WMI driver in the Linux kernel manages laptop power profiles and events. During system suspend, a NULL pointer dereference can cause a kernel crash that halts the suspend sequence, potentially leaving the system in an inconsistent state or unable to sleep properly.
Technical details
The vulnerability is a NULL pointer dereference in the platform/x86/bitland-mifs-wmi driver that occurs during suspend/resume operations. The driver registers two WMI devices (control and event); during probe, the event device returns early without initializing the platform profile device (data->pp_dev). However, PM sleep callbacks are registered globally and trigger for both devices. When suspend is invoked on the event device, bitland_mifs_wmi_suspend() passes the NULL pp_dev to laptop_profile_get(), causing a crash in dev_get_drvdata(). The fix adds a validity check for data->pp_dev in both suspend and resume callbacks to safely skip operations for the event device. This is a low-risk code path issue that requires the system to suspend while the driver is loaded.
Affected products
- Linux Linux kernel 5.x, 6.x, 7.x and later (bitland-mifs-wmi driver present)
Timeline
- 2026-08-15: disclosed
- 2026-07-03: patched