CVE-2023-54220: serial: 8250: Fix oops for port->pm on uart_change_pm()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-30 · updated 2026-10-28

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().

Affected products

Linux kernel: from 4.14.316 before 4.14.324; from 4.19.284 before 4.19.293; from 5.4.244 before 5.4.255; from 5.10.181 before 5.10.192; from 5.15.113 before 5.15.128; from 6.1.30 before 6.1.47 — fixed in 4.14.324, 4.19.293, 5.10.192, 5.15.128, 5.4.255, 6.1.47

How to fix

Upgrade to a fixed version: Linux kernel 4.14.324, 4.19.293, 5.10.192, 5.15.128. Check the vendor advisory for mitigations.

References

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