CVE intelligence and bounded remediation

CVE-2025-21902 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: acpi: typec: ucsi: Introduce a ->poll_cci method For the ACPI backend of UCSI the UCSI "registers" are just a memory copy of the register values in an opregion. The ACPI implementation in the BIOS ensures that the opregion contents are synced to the embedded controller and it ensures that the registers (in particular CCI) are synced back to the opregion on notifications. While there is an ACPI call that syncs the actual registers to the opregion there is rarely a need to do this and on some ACPI implementations it actually breaks in various interesting ways. The only reason to force a sync from the embedded controller is to poll CCI while notifications are disabled. Only the ucsi core knows if this is the case and guessing based on the current command is suboptimal, i.e. leading to the following spurious assertion splat: WARNING: CPU: 3 PID: 76 at drivers/usb/typec/ucsi/ucsi.c:1388 ucsi_reset_ppm+0x1b4/0x1c0 [typec_ucsi] CPU: 3 UID: 0 PID: 76 Comm: kworker/3:0 Not tainted 6.12.11-200.fc41.x86_64 #1 Hardware name: LENOVO 21D0/LNVNB161216, BIOS J6CN45WW 03/17/2023 Workqueue: events_long ucsi_init_work [typec_ucsi] R…

Severity
Medium
CVSS
5.5 (3.1)
Published
2025-04-01
CISA KEV
Not currently listed
Ecosystem
linux/kernel

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 6.14

Showing 2 representative product identities from 7 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

General vulnerability remediation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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