CVE intelligence and bounded remediation

CVE-2025-21661 — Linux Linux Kernel security vulnerability

Medium CVSS 5.5

In the Linux kernel, the following vulnerability has been resolved: gpio: virtuser: fix missing lookup table cleanups When a virtuser device is created via configfs and the probe fails due to an incorrect lookup table, the table is not removed. This prevents subsequent probe attempts from succeeding, even if the issue is corrected, unless the device is released. Additionally, cleanup is also needed in the less likely case of platform_device_register_full() failure. Besides, a consistent memory leak in lookup_table->dev_id was spotted using kmemleak by toggling the live state between 0 and 1 with a correct lookup table. Introduce gpio_virtuser_remove_lookup_table() as the counterpart to the existing gpio_virtuser_make_lookup_table() and call it from all necessary points to ensure proper cleanup.

Severity
Medium
CVSS
5.5 (3.1)
Published
2025-01-21
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-401

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 6.13

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

Matched remediation archetype

Resource exhaustion and denial of service

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

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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