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.

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Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8593-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8603-1 Linux kernel (Azure) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 21 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-184
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Sun, 19 Jul 2026 09:15:00 +0000

Type Values Removed Values Added
Description 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.
Title perf/x86/intel: Improve validation and configuration of ACR masks
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-07-19T09:10:30.990Z

Reserved: 2026-06-09T07:44:35.401Z

Link: CVE-2026-53370

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Low

Publid Date: 2026-07-19T00:00:00Z

Links: CVE-2026-53370 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-07-22T00:45:03Z

Weaknesses