CVE-2023-52811 scsi: ibmvfc: Remove BUG_ON in the case of an empty event pool

Medium 5.5 Published Updated

A missing null check in the ibmvfc driver can cause a kernel crash when the event pool is empty, leading to denial of service.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2023-52811?

CVE-2023-52811 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

scsi: ibmvfc: Remove BUG_ON in the case of an empty event pool

In practice the driver should never send more commands than are allocated to a queue's event pool. In the unlikely event that this happens, the code asserts a BUG_ON, and in the case that the kernel is not configured to crash on panic returns a junk event pointer from the empty event list causing things to spiral from there. This BUG_ON is a historical artifact of the ibmvfc driver first being upstreamed, and it is well known now that the use of BUG_ON is bad practice except in the most unrecoverable scenario. There is nothing about this scenario that prevents the driver from recovering and carrying on.

Remove the BUG_ON in question from ibmvfc_get_event() and return a NULL pointer in the case of an empty event pool. Update all call sites to ibmvfc_get_event() to check for a NULL pointer and perfrom the appropriate failure or recovery action.

Weakness: CWE-476

Which versions are affected by CVE-2023-52811?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-52811?

Apply the vendor's patch.

Is CVE-2023-52811 being exploited?

There is no known exploitation of CVE-2023-52811 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2023-52811, DEBIAN-CVE-2023-52811, GHSA-j7xm-pf76-qww8, ROOT-OS-DEBIAN-11-CVE-2023-52811, UBUNTU-CVE-2023-52811.

Is CVE-2023-52811 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free