CVE-2026-64290

Analyzed Analyzed - Analysis Complete

iommufd Fault Group Read Loop Failure in Linux Kernel

Publication date: 2026-07-25

Last updated on: 2026-08-12

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: iommufd: Break the loop on failure in iommufd_fault_fops_read() On a copy_to_user() failure inside the inner list_for_each_entry, only the inner loop breaks; the outer while re-fetches the just-restored fault group and retries the failing copy_to_user() forever, spinning the reader at 100% CPU with fault->mutex held. Check rc after the inner loop and break the outer while as well.

CVSS Scores

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Meta Information

Published

2026-07-25

Last Modified

2026-08-12

Generated

2026-08-14

AI Q&A

2026-07-25

EPSS Evaluated

2026-08-13

NVD

CVE-2026-64290

EUVD

EUVD-2026-49002

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 6.13 (inc) to 6.18.39 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.1.4 (exc)
linux	linux_kernel	From 6.11 (inc) to 6.12.101 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-835	The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a flaw in the iommufd subsystem. When a copy_to_user() operation fails inside a loop, only the inner loop breaks but the outer loop continues retrying the same operation indefinitely. This causes the reader process to consume 100% CPU while holding a mutex lock, leading to a system hang or denial of service.

Detection Guidance

This vulnerability is specific to the Linux kernel's iommufd subsystem and may not have direct network detection methods. Monitor for high CPU usage in processes interacting with iommufd, kernel logs for fault-related errors, or system hangs during memory fault handling. Check kernel version against patched releases.

Impact Analysis

This vulnerability can cause system instability by consuming excessive CPU resources and locking system resources indefinitely. It may lead to denial of service conditions where affected systems become unresponsive or crash.

Mitigation Strategies

Update the Linux kernel to the latest stable version that includes the fix for this issue. If immediate patching is not possible, restrict access to iommufd functionality or disable affected services until the kernel is updated.

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