Linux Kernel DAMON Region Size Validation Flaw

Publication date: 2026-06-09

Last updated on: 2026-07-08

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: mm/damon/core: disallow non-power of two min_region_sz on damon_start() Commit d8f867fa0825 ("mm/damon: add damon_ctx->min_sz_region") introduced a bug that allows unaligned DAMON region address ranges. Commit c80f46ac228b ("mm/damon/core: disallow non-power of two min_region_sz") fixed it, but only for damon_commit_ctx() use case. Still, DAMON sysfs interface can emit non-power of two min_region_sz via damon_start(). Fix the path by adding the is_power_of_2() check on damon_start(). The issue was discovered by sashiko [1].

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-06-09

Last Modified

2026-07-08

Generated

2026-07-20

AI Q&A

2026-06-09

EPSS Evaluated

2026-07-18

NVD

CVE-2026-52905

EUVD

EUVD-2026-35434

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 6.18 (inc) to 6.18.30 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.0.4 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-1284	The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Linux kernel's DAMON (Data Access MONitor) subsystem. A recent code change introduced a bug that allows unaligned DAMON region address ranges by not properly enforcing that the minimum region size (min_region_sz) is a power of two when starting DAMON monitoring via the damon_start() function. Although a fix was applied for one use case (damon_commit_ctx()), the damon_start() path still allowed non-power of two values, which was corrected by adding a check to ensure min_region_sz is a power of two.

Impact Analysis

The vulnerability could lead to improper or unexpected behavior in the DAMON subsystem due to unaligned memory region monitoring. This might affect the accuracy or reliability of memory access monitoring, potentially causing system instability or incorrect performance data. However, no specific impacts such as privilege escalation or data leakage are described.

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