In the Linux kernel, the following vulnerability has been resolved: cxl/mbox: Break poison list loop on an empty payload A device that ret

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

cxl/mbox: Break poison list loop on an empty payload

A device that returns count == 0 with CXL_POISON_FLAG_MORE set on every
iteration never advances nr_records, so the max_errors guard never
trips and the do/while loops forever while holding poison.mutex. That
hangs the sysfs-triggered scan thread and blocks all subsequent poison
operations on the device. The existing "Protect against an uncleared
_FLAG_MORE" guard was intended to bound a misbehaving device but does
not cover the count == 0 case.

Stop the loop on an empty payload so a malfunctioning or malicious
device cannot wedge the poison scan.