perf/ftrace: Fix WARNING in __unregister_ftrace_function
Published Sep 24, 2026 · Updated Sep 24, 2026
In the Linux kernel, the following vulnerability has been resolved:
Summary
What happened
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.
The record
- CVE
- CVE-2026-97443
- Published
- Sep 24, 2026
- Updated
- Sep 24, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 24, 2026CVE publishedPublication date reported by the CVE source.
- Sep 24, 2026Record updatedLatest update available in the CVE record.
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- Affected versionversion=0 <6.12.111
- Affected versionversion=0 <6.18.53
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7f845820afaad339341c2ae42bc7fdec175df9ea
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9581123304b23049437324038698af9fb56ee663
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <df097713b56ffac5eed32a9be2e7d27ac48d9087
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