CVE-2023-54220 serial: 8250: Fix oops for port->pm on uart_change_pm()
A null pointer dereference in the Linux kernel 8250 serial driver causes a system crash when unloading specific hardware drivers.
- 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-2023-54220?
CVE-2023-54220 is a high-severity vulnerability in Linux, published on 30 Dec 2025. 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:
serial: 8250: Fix oops for port->pm on uart_change_pm()
Unloading a hardware specific 8250 driver can produce error "Unable to handle kernel paging request at virtual address" about ten seconds after unloading the driver. This happens on uart_hangup() calling uart_change_pm().
Turns out commit 04e82793f068 ("serial: 8250: Reinit port->pm on port specific driver unbind") was only a partial fix. If the hardware specific driver has initialized port->pm function, we need to clear port->pm too. Just reinitializing port->ops does not do this. Otherwise serial8250_pm() will call port->pm() instead of serial8250_do_pm().
Which versions are affected by CVE-2023-54220?
How do I fix CVE-2023-54220?
Apply the vendor's patch.
Is CVE-2023-54220 being exploited?
There is no known exploitation of CVE-2023-54220 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54220, DEBIAN-CVE-2023-54220, GHSA-ghxp-vq7f-3f7c, UBUNTU-CVE-2023-54220.