CVE-2026-53370

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.

CVSS 3.1

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

EPSS

0.12% probability · 2th percentile

CISA KEV

Not listed

Affected

linux/linux kernel

Source

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.