Bug 2363289 (CVE-2025-23147)

Summary: CVE-2025-23147 kernel: i3c: Add NULL pointer check in i3c_master_queue_ibi()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: low    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-05-01 14:02:23 UTC 
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.
Comment 1 Avinash Hanwate 2025-05-02 04:57:01 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025050126-CVE-2025-23147-cfd5@gregkh/T