tracing: Free histogram the var ref when its initialization fails
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 4 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.20
- Fix · CNA Linux (Linux) 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
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-97923
- 2026-10-03 Alias added: GHSA-28hv-8h97-8cx6
- 2026-10-03 Fix available: Linux/Linux@352f84a381e7b4651b30366e93cb858f3fa9c91a, Linux/Linux@4870f9071c9ea3c1423a07741b85a794db30d672, Linux/Linux@4924328d6991f25b65bb7c8ff5d56c2a9b254851 +5 · CNA
- 2026-10-03 4 new references · CNA
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-11-07 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/608b7751926ec08fae6a1ac4e7308195da68c362
- https://git.kernel.org/stable/c/4870f9071c9ea3c1423a07741b85a794db30d672
- https://git.kernel.org/stable/c/352f84a381e7b4651b30366e93cb858f3fa9c91a
- https://git.kernel.org/stable/c/4924328d6991f25b65bb7c8ff5d56c2a9b254851
- https://git.kernel.org/stable/c/74375caa20fe5165807b4334c783d1790b01f02a
- https://git.kernel.org/stable/c/222abcbe7866fef04563b6eb89fb21f627dcbc77
- https://git.kernel.org/stable/c/a69baeac38677270656e85753d93856a076dee57
- https://git.kernel.org/stable/c/516001d53e6b2ea95a251ee2ef54a1a689a3fd58
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Sources
- CVE-2026-97923 · CVE Program
- CVE-2026-97923 · NVD
- FIRST EPSS
- GHSA-28hv-8h97-8cx6 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-97923 · Red Hat security data · CC BY 4.0
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