CVE-2025-23147

About vulnerability

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.

Affected product:

AlmaLinux 9.2 ESU , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 20.04 ELS

Affected packages:

kernel-uek @ 5.4.17 (+3 more)

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.