CVE-2026-97923
In the Linux kernel, the following vulnerability has been resolved: tracing: Free histogram the var ref when its initialization fails create_var_ref() allocates a VAR_REF hist_field and then calls init_var_ref() to fill it in. When that fails the field is leaked. commit 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy var_refs") made destroy_hist_field() return early for HIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger's var_refs[] array instead. create_var_ref() adds the field to that array only after init_var_ref() has succeeded, so on this path the field is in neither place and nothing frees it. The call was correct when it was written, before var refs were taken out of destroy_hist_field(). init_var_ref() cannot free it either. The caller owns the field, so init_var_ref() undoes only its own string allocations and leaves the field alone. Freeing it there would leave create_var_ref() passing freed memory to destroy_hist_field(), which reads its flags. Call __destroy_hist_field(), which frees the field without consulting the flag.
Affected versions
Linux kernel versions
4.19.100,
5.0
and later are affected. Fixed in
5.10.271,
5.15.222,
6.1.189,
6.6.158,
6.12.111,
6.18.53,
7.2.7,
7.3-rc3
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-97923?
CVE-2026-97923 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.19.100 onward and has been patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-97923 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-97923?
Yes. CVE-2026-97923 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 4.19.100 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-97923 actively exploited?
No. CVE-2026-97923 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.