Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
Input: sur40 - fix input device registration ordering
In sur40_probe(), input_register_device() was previously called early before the V4L2 video device and vb2_queue components were fully initialized. If userspace opened the input device immediately upon registration, sur40_open() would trigger and start the sur40_poll() worker thread. This worker thread invokes sur40_process_video() and accesses the uninitialized vb2_queue structure, leading to a data race and potential system crash.
Furthermore, if V4L2 or video registration failed after input_register_device() succeeded, the error path fell through to calling input_free_device() on a successfully registered device instead of input_unregister_device(), corrupting input core state.
Move input_register_device() to the very end of sur40_probe(). This ensures the V4L2 and video queue structures are fully initialized before polling can start, and naturally resolves the error path bug since input_free_device() is now only called when input registration has not yet occurred.
To maintain strict LIFO (Last-In, First-Out) teardown ordering, also move input_unregister_device() to the very beginning of sur40_disconnect(). This guarantees that the input polling worker thread is stopped before V4L2 video components or control handlers are unregistered.
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+5 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |