CVE-2023-52922

A flaw was found in the Linux kernel's Controller Area Network (CAN) Broadcast Manager (BCM) module. A local attacker with low privileges could exploit a use-after-free vulnerability in the bcm_proc_show() function. This occurs because the bcm_op object is freed before its corresponding procfs entry is removed, allowing a subsequent read operation to access freed memory. This flaw could lead to a denial of service, information disclosure, or potentially arbitrary code execution and privilege escalation.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this vulnerability, prevent the bcm kernel module from loading by blacklisting it. Create a file named /etc/modprobe.d/blacklist-bcm.conf with the following content:

blacklist bcm

After creating the file, regenerate the initramfs and reboot the system for the changes to take effect. This mitigation may impact systems that rely on CAN BCM functionality. If CAN BCM is required, this mitigation is not suitable. A system reboot is required for the changes to take effect.