UBUNTU-CVE-2025-23147

In the Linux kernel, the following vulnerability has been resolved: i3c: Add NULL pointer check in i3c_master_queue_ibi() The I3C master driver may receive an IBI from a target device that has not been probed yet. In such cases, the master calls i3c_master_queue_ibi() to queue an IBI work task, leading to "Unable to handle kernel read from unreadable memory" and resulting in a kernel panic. Typical IBI handling flow: 1. The I3C master scans target devices and probes their respective drivers. 2. The target device driver calls i3c_device_request_ibi() to enable IBI and assigns dev->ibi = ibi. 3. The I3C master receives an IBI from the target device and calls i3c_master_queue_ibi() to queue the target device driver’s IBI handler task. However, since target device events are asynchronous to the I3C probe sequence, step 3 may occur before step 2, causing dev->ibi to be NULL, leading to a kernel panic. Add a NULL pointer check in i3c_master_queue_ibi() to prevent accessing an uninitialized dev->ibi, ensuring stability.