CVE-2026-64334: USB: serial: digi_acceleport: fix hard lockup on disconnect
In the Linux kernel, the following vulnerability has been resolved:
USB: serial: digiacceleport: fix hard lockup on disconnect
If submitting the OOB write urb fails persistently (e.g if the device is being disconnected) the driver would loop indefinitely with interrupts disabled.
Check for urb submission errors when sending OOB commands to avoid hanging if, for example, open(), settermios() or close() races with a physical disconnect.
This is issue was flagged by Sashiko when reviewing an unrelated change to the driver.
Affected Software
Remediation
Event History
Frequently Asked Questions
What conditions are required to trigger the hard lockup?
An attacker or local user needs access sufficient to operate the affected Digi AccelePort USB serial device. The lockup can occur when an OOB write URB submission fails persistently while operations such as open(), set_termios(), or close() race with a physical device disconnect.
What is the practical impact of successful exploitation?
The affected driver can enter an indefinite loop with interrupts disabled, resulting in a hard lockup and loss of system availability. The provided CVSS vector indicates local attack access, low attack complexity, low privileges required, and no confidentiality or integrity impact.
How can I determine whether a system is exposed?
A system is potentially exposed if it runs the Linux kernel and uses the digi_acceleport USB serial driver with a connected or disconnectable Digi AccelePort device. The issue is specifically associated with failed OOB write URB submissions during device-disconnect races.
What remediation is available?
A patch is available. The fix checks URB submission errors when sending OOB commands so the driver does not loop indefinitely when submission fails during a disconnect.