linux-cve-announce - CVE-2025-38519: mm/damon: fix divide by zero in damon_get_intervals

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2025081654-CVE-2025-38519-6cc4@gregkh>
Date: Sat, 16 Aug 2025 12:58:01 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2025-38519: mm/damon: fix divide by zero in damon_get_intervals_score()

From: Greg Kroah-Hartman <gregkh@...nel.org>

Description
===========

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

mm/damon: fix divide by zero in damon_get_intervals_score()

The current implementation allows having zero size regions with no special
reasons, but damon_get_intervals_score() gets crashed by divide by zero
when the region size is zero.

  [   29.403950] Oops: divide error: 0000 [#1] SMP NOPTI

This patch fixes the bug, but does not disallow zero size regions to keep
the backward compatibility since disallowing zero size regions might be a
breaking change for some users.

In addition, the same crash can happen when intervals_goal.access_bp is
zero so this should be fixed in stable trees as well.

The Linux kernel CVE team has assigned CVE-2025-38519 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.15 with commit f04b0fedbe714f822bd066b319a60faa39a985a1 and fixed in 6.15.7 with commit ca4bb9ac706f05ead8ac1cce7b8245fc0645a687
	Issue introduced in 6.15 with commit f04b0fedbe714f822bd066b319a60faa39a985a1 and fixed in 6.16 with commit bd225b9591442065beb876da72656f4a2d627d03

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2025-38519
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	mm/damon/core.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/ca4bb9ac706f05ead8ac1cce7b8245fc0645a687
	https://git.kernel.org/stable/c/bd225b9591442065beb876da72656f4a2d627d03