CVE-2026-72105

Received Received - Intake

dm-log bitset_size overflow fix in Linux kernel

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: dm-log: fix a bitset_size overflow on 32bit machines Commit c20e36b7631d ("dm log: fix out-of-bounds write due to region_count overflow") made sure that region_count could fit in an unsigned int. But the bitmap memory isn't allocated based on region_count. It uses bitset_size (a size_t variable). The first step of calculating bitset_size is to set it to region_count, rounded up to a multiple of BITS_PER_LONG. If region_size is less than BITS_PER_LONG smaller than UINT_MAX, it will get rounded up to 2^32. On a 32bit architecture, this will make bitset_size wrap around to 0 and fail, despite region_count being valid. Since bitset_size gets divided by 8, it can hold any valid region_count. It just needs a special case to handle the rollover. If it is 0, the value rolled over, and bitset size should be set to the number of bytes needed to hold 2^32 bits.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-72105

EUVD

EUVD-2026-59063

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability is in the Linux kernel's device mapper logging (dm-log) component. It occurs when a 32-bit system calculates the size of a bitmap needed to track regions. The calculation can overflow, causing the size to wrap around to zero. This leads to incorrect memory allocation and potential out-of-bounds writes.

Detection Guidance

This vulnerability affects the Linux kernel's device mapper logging (dm-log) component on 32-bit systems. Detection requires checking kernel version and device mapper logs for related errors. Use commands like 'uname -a' to verify 32-bit kernel and 'dmesg | grep dm-log' to check for related errors.

Impact Analysis

On 32-bit Linux systems, this flaw could cause kernel memory corruption or crashes due to incorrect bitmap size handling. Attackers with local access might exploit it to escalate privileges or cause denial-of-service conditions.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA. It is a low-level kernel memory issue that could lead to system instability or crashes on 32-bit machines, but there is no evidence it impacts data privacy or security controls required by these regulations.

Mitigation Strategies

Apply the kernel patch that fixes the bitset_size overflow issue. Update to a patched kernel version. If using device mapper, ensure region_count values are validated to prevent overflow. Monitor logs for any related errors after patching.

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