Linux Kernel Synaptics Pass-Through Port Crash Vulnerability

A vulnerability in the Linux kernel's synaptics input driver can lead to a crash when enabling a pass-through port. This issue occurs because an interrupt may arrive before the psmouse driver has fully bound to the port. The synaptics sub-driver attempts to access the psmouse instance related to the port to determine whether to forward a single byte or an entire protocol packet. If the psmouse instance is not yet attached, this can result in a crash. The vulnerability affects several versions of the Linux kernel.

Impact

The vulnerability can cause a system crash by disrupting the normal operation of the psmouse driver when a pass-through port is enabled.