CVE-2025-21746: linux kernel — Fix

Description

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 serio_open() only after attaching psmouse instance to serio port instance this prevents the potential crash.

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CVSS v3.1 Score

4.7

MEDIUM

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-367 CWE-367

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.5 — 6.6.80
linux	linux_kernel	6.7 — 6.12.17
linux	linux_kernel	6.13 — 6.13.3

References

Advisories & Patches

https://git.kernel.org/stable/c/08bd5b7c9a2401faabdaa1472d45c7de0755fd7e https://git.kernel.org/stable/c/3e179d3f1ada963475395d81bfe91daef4d1a24c https://git.kernel.org/stable/c/87da1ea93ec9f9f0004e5b12e78789bc94e360bf https://git.kernel.org/stable/c/a2cbcd70133dc0d4d4c95ad4cd5412b935354c7c

Frequently Asked Questions

What is CVE-2025-21746? +

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 serio_open() only after attaching psmouse instance to serio port instance this prevents the potential crash. It has a CVSS v3.1 base score of 4.7 (MEDIUM).

How severe is CVE-2025-21746? +

CVE-2025-21746 has a CVSS v3.1 score of 4.7 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-21746? +

CVE-2025-21746 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-21746? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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