---
id: CVE-2026-53370
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  perf/x86/intel: Improve validation and configuration of ACR masks

  Currently there are several issues on the user space ACR mask validation
  and configuration.
  - The val…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  perf/x86/intel: Improve validation and configuration of ACR masks

  Currently there are several issues on the user space ACR mask validation
  and configuration.
  - The val…
severity: none
published: '2026-07-19'
updated: '2026-07-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53370'
references:
  - url: 'https://git.kernel.org/stable/c/5ad732a56be46aabf158c16aa0c095291727aaef'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/aab56b95bee3ff79176b13443cd9d7cfe9747df0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c05e01cef47d9b4969eae2dcf9467e2a555bcb4f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00124
epssPercentile: 0.02452
ingestedAt: '2026-07-19T14:31:07.410Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

perf/x86/intel: Improve validation and configuration of ACR masks

Currently there are several issues on the user space ACR mask validation
and configuration.
- The validation for user space ACR mask (attr.config2) is incomplete,
  e.g., the ACR mask could include the index which belongs to another
  ACR events group, but it's not validated.
- An early return on an invalid ACR mask caused all subsequent ACR groups
  to be skipped.
- The stale hardware ACR mask (hw.config1) is not cleared before setting
  new hardware ACR mask.

The following changes address all of the above issues.
- Figure out the event index group of an ACR group. Any bits in the
  user-space mask not present in the index group are now dropped.
- Instead of an early return on invalid bits, drop only the invalid
  portions and continue iterating through all ACR events to ensure full
  configuration.
- Explicitly clear the stale hardware ACR mask for each event prior to
  writing the new configuration.

Besides, a non-leader event member of ACR group could be disabled in
theory. This could cause bit-shifting errors in the acr_mask of remaining
group members. But since ACR sampling requires all events to be active,
this should not be a big concern in real use case. Add a "FIXME" comment
to notice this risk.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.