CVE-2026-72040

Received Received - Intake

Reference Count Leak in Linux Kernel IPMI Subsystem

Publication date: 2026-08-15

Last updated on: 2026-08-23

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: ipmi: fix refcount leak in i_ipmi_request() When a caller provides a `supplied_recv` message to i_ipmi_request(), the function increments the user's `nr_msgs` reference count. If an error occurs later, the out_err cleanup path only frees the recv_msg if the function allocated it itself (i.e., !supplied_recv). In the supplied_recv case the cleanup is skipped, leaving the reference count elevated. The caller ipmi_request_supply_msgs() does not release the supplied_recv on error, so the reference is permanently leaked. Fix this by explicitly reverting the reference count operations when a supplied recv_msg with a valid user pointer is present in the error path: decrement nr_msgs and drop the user's kref.

CVSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-23

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-72040

EUVD

EUVD-2026-58998

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 is a reference count leak in the Linux kernel's IPMI (Intelligent Platform Management Interface) subsystem. When a caller provides a pre-allocated message buffer to the i_ipmi_request function, the function incorrectly increments the user's message reference count but fails to decrement it if an error occurs later. This leaves the reference count elevated, causing a permanent leak since the caller does not release the buffer on error.

Detection Guidance

This vulnerability is specific to the Linux kernel's IPMI subsystem and involves a reference count leak. Detection requires checking kernel logs for IPMI-related errors or monitoring for unexpected memory usage growth in kernel processes. Commands like dmesg | grep -i ipmi or checking /var/log/kern.log for IPMI errors may help identify issues.

Impact Analysis

This vulnerability could lead to resource exhaustion in the kernel, potentially causing system instability or crashes. It may degrade performance by wasting memory and could trigger unexpected behavior in applications relying on IPMI functionality.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA as it is a low-level kernel reference count leak in the IPMI subsystem. It may indirectly impact availability but does not involve data exposure or unauthorized access.

Mitigation Strategies

Apply the latest kernel update from your Linux distribution to patch this vulnerability. If immediate patching is not possible, consider disabling the IPMI subsystem if not in use by blacklisting the ipmi_devintf and ipmi_si modules.

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