CVE-2026-74471: tracing: Check return value of __register_event() in trace_module_add_events()
In the Linux kernel, the following vulnerability has been resolved:
tracing: Check return value of registerevent() in tracemoduleaddevents()
tracemoduleaddevents() ignores the return value of registerevent() and unconditionally calls addeventtotracers() for each event.
If registerevent() fails (for example, if eventinit() fails), the traceeventcall is not added to ftraceevents list, but addeventtotracers() still creates a traceeventfile pointing to it. If module loading subsequently fails and module memory is freed, tracing state retains a stale traceeventcall pointer in traceeventfile, leading to a use-after-free when tracefs or tracing subsystem operations are later executed.
Fix this by checking the return value of registerevent() and only calling addeventtotracers() if event registration succeeded.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Update the tracing code so trace_module_add_events() checks the return value of __register_event(); only call __add_event_to_tracers() when __register_event() succeeds. This prevents __add_event_to_tracers() from creating/using trace_event_file entries with stale trace_event_call pointers after module loading failures that free module memory.
Linux kernel tracing (trace_module_add_events / __register_event) __register_event() return-value handling = Check return value and call __add_event_to_tracers() only if event registration succeeded
Event History
Frequently Asked Questions
What is the severity of CVE-2026-74471?
The severity of CVE-2026-74471 is rated at 48.
How do I fix CVE-2026-74471?
To fix CVE-2026-74471, ensure that your system is updated to the latest version of the Linux kernel that includes the patch.
What systems are affected by CVE-2026-74471?
CVE-2026-74471 affects all supported versions of the Linux kernel.
What type of vulnerability is CVE-2026-74471?
CVE-2026-74471 is classified as a Use After Free vulnerability.
What is the impact of CVE-2026-74471 on system security?
The impact of CVE-2026-74471 could potentially lead to arbitrary code execution or system compromise due to improper event registration handling.