Bug 2460642 (CVE-2026-31480)

Summary: CVE-2026-31480 kernel: tracing: Fix potential deadlock in cpu hotplug with osnoise
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel. A local attacker or a user with specific privileges could exploit a race condition during CPU hotplug operations, specifically when using the 'osnoise' tracing feature. This vulnerability can lead to a system deadlock, rendering the system unresponsive and requiring a reboot.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-04-22 15:02:36 UTC
In the Linux kernel, the following vulnerability has been resolved:

tracing: Fix potential deadlock in cpu hotplug with osnoise

The following sequence may leads deadlock in cpu hotplug:

    task1        task2        task3
    -----        -----        -----

 mutex_lock(&interface_lock)

            [CPU GOING OFFLINE]

            cpus_write_lock();
            osnoise_cpu_die();
              kthread_stop(task3);
                wait_for_completion();

                      osnoise_sleep();
                        mutex_lock(&interface_lock);

 cpus_read_lock();

 [DEAD LOCK]

Fix by swap the order of cpus_read_lock() and mutex_lock(&interface_lock).