CVE-2025-21746: Input: synaptics - fix crash when enabling pass-through port
In the Linux kernel, the following vulnerability has been resolved:
Input: synaptics - fix crash when enabling pass-through port
When enabling a pass-through port an interrupt might come before psmouse driver binds to the pass-through port. However synaptics sub-driver tries to access psmouse instance presumably associated with the pass-through port to figure out if only 1 byte of response or entire protocol packet needs to be forwarded to the pass-through port and may crash if psmouse instance has not been attached to the port yet.
Fix the crash by introducing open() and close() methods for the port and check if the port is open before trying to access psmouse instance. Because psmouse calls serioopen() only after attaching psmouse instance to serio port instance this prevents the potential crash.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-21746?
CVE-2025-21746 is classified as a moderate severity vulnerability in the Linux kernel.
How do I fix CVE-2025-21746?
To fix CVE-2025-21746, update your Linux kernel to the latest version that addresses this vulnerability.
What type of flaw is CVE-2025-21746?
CVE-2025-21746 is a flaw related to improper handling of interrupts in the synaptics driver during pass-through port activation.
Which versions of the Linux kernel are affected by CVE-2025-21746?
CVE-2025-21746 affects multiple versions of the Linux kernel prior to the resolution in the latest updates.
Can CVE-2025-21746 lead to system instability?
Yes, CVE-2025-21746 can potentially lead to system crashes or instability when enabling the pass-through port.