Executive brief
A vulnerability in the Linux kernel's Digi AccelePort USB serial driver can cause a system to completely freeze (hard lockup) when the device is physically disconnected. This occurs because the driver enters an infinite loop while interrupts are disabled, effectively halting all system operations. To recover, a user would typically need to perform a hard reboot of the affected machine.
Technical details
A vulnerability in the 'digi_acceleport' USB serial driver (drivers/usb/serial/digi_acceleport.c) causes a hard lockup when a device is disconnected. The root cause is a failure to check the return value of 'usb_submit_urb' when sending Out-of-Band (OOB) commands. If URB submission fails persistently (common during physical disconnection), the driver enters an infinite loop within 'digi_write_oob_command' while holding a spinlock with interrupts disabled ('spin_lock_irqsave'). This results in a kernel hang that requires a hard reset. The fix involves checking for submission errors and breaking the loop if 'usb_submit_urb' fails.
Affected products
- Linux Linux Kernel 2.6.12 through 6.10.x
Timeline
- 2026-06-23: patched: Initial patch authored by Johan Hovold
- 2026-07-25: advisory: CVE-2026-64334 published
References
- https://git.kernel.org/stable/c/2067b3838da6e4af03bae3630414193188d754b2
- https://git.kernel.org/stable/c/2b7dc482f859f2d027db07ff0efc1c5df5b3451a
- https://git.kernel.org/stable/c/5a82d842e8c35227d7227f19e5e654df1451782c
- https://git.kernel.org/stable/c/5c1ea24b53bf3bfb859f0a05573997487975da23
- https://git.kernel.org/stable/c/6a8592ace932081ea11aea41c460a1ca0f6344a4
- https://git.kernel.org/stable/c/6e51147c2744d15730084dc89cc99180d3de4184
- https://git.kernel.org/stable/c/79bc131df0e50f8f663c1fdbbe952aaf193a8d39