In the Linux kernel, the following vulnerability has been resolved:

perf/ftrace: Fix WARNING in __unregister_ftrace_function

perf_ftrace_function_unregister() unconditionally calls
unregister_ftrace_function() without checking whether the ftrace_ops
was ever successfully registered. This triggers a WARN_ON in
__unregister_ftrace_function() when the ops doesn't have
FTRACE_OPS_FL_ENABLED set.

This can happen during perf_event_alloc() error cleanup when
perf_trace_destroy() is called via __free_event() on an event whose
ftrace_ops registration failed or was already torn down by
perf_try_init_event()'s err_destroy path.

The call path is:
perf_event_alloc() error cleanup
-> __free_event()
-> event->destroy() [tp_perf_event_destroy]
-> perf_trace_destroy()
-> perf_trace_event_close()
-> TRACE_REG_PERF_CLOSE
-> perf_ftrace_function_unregister()
-> unregister_ftrace_function()
-> __unregister_ftrace_function()
-> WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))

Fix this by checking FTRACE_OPS_FL_ENABLED before attempting to
unregister. If the ops is not enabled, just free the filter and
return success.
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Ubuntu USN Ubuntu USN USN-8961-1 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 01 Oct 2026 15:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-398

Wed, 30 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-617
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Fri, 25 Sep 2026 04:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-398

Thu, 24 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: perf/ftrace: Fix WARNING in __unregister_ftrace_function perf_ftrace_function_unregister() unconditionally calls unregister_ftrace_function() without checking whether the ftrace_ops was ever successfully registered. This triggers a WARN_ON in __unregister_ftrace_function() when the ops doesn't have FTRACE_OPS_FL_ENABLED set. This can happen during perf_event_alloc() error cleanup when perf_trace_destroy() is called via __free_event() on an event whose ftrace_ops registration failed or was already torn down by perf_try_init_event()'s err_destroy path. The call path is: perf_event_alloc() error cleanup -> __free_event() -> event->destroy() [tp_perf_event_destroy] -> perf_trace_destroy() -> perf_trace_event_close() -> TRACE_REG_PERF_CLOSE -> perf_ftrace_function_unregister() -> unregister_ftrace_function() -> __unregister_ftrace_function() -> WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)) Fix this by checking FTRACE_OPS_FL_ENABLED before attempting to unregister. If the ops is not enabled, just free the filter and return success.
Title perf/ftrace: Fix WARNING in __unregister_ftrace_function
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-25T12:44:20.881Z

Reserved: 2026-09-24T14:53:16.870Z

Link: CVE-2026-97443

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-24T17:17:22.550

Modified: 2026-09-25T13:17:28.023

Link: CVE-2026-97443

cve-icon Redhat

Severity : Low

Publid Date: 2026-09-24T00:00:00Z

Links: CVE-2026-97443 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-01T17:15:10Z

Weaknesses