CVE-2026-93283
Description
A flaw was found in the Linux kernel's I3C (Improved Inter-Integrated Circuit) master subsystem. This issue can result in a Denial of Service (DoS) caused by a system crash. When device registration fails, the driver frees the device object but fails to clear internal pointers referencing the freed memory. A local user could exploit this dangling reference during subsequent device unregistration to trigger a use-after-free condition.
Mitigation
To mitigate this vulnerability, prevent the I3C subsystem kernel module from loading on systems where I3C hardware is not required:
1. Create a configuration file to disable the module:
# echo "install i3c /bin/true" > /etc/modprobe.d/disable-i3c.conf
2. Blacklist the module:
# echo "blacklist i3c" >> /etc/modprobe.d/disable-i3c.conf
3. If the module is already loaded, unload it:
# modprobe -r i3c
Caveat: Disabling the i3c module prevents the operating system from recognizing and communicating with attached I3C devices and bus controllers. If the module cannot be unloaded because it is in use or built into the active kernel, a system restart is required for these settings to take effect.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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