NULL pointer dereference in Linux kernel s390 debug feature
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
- —
- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 5 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel is affected from 5.15 before the fixed releases listed in the solution. When debug_register_static() fails in the s390 debug feature, it clears the area pointers but leaves the area bounds unchanged, so copying such an area dereferences NULL pointers. Opening the area's view file or calling debug_dump() triggers the NULL pointer dereference.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: s390/debug: Fix NULL pointer dereference in debug_info_copy() When debug_register_static() fails, it clears areas, active_pages and active_entries but leaves the area bounds unchanged. Copying such an area, either by opening its view file or via debug_dump(), makes debug_info_copy() dereference the NULL pointers. Skip the copy loop when the source has no areas.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade the Linux kernel to 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9 or 7.3, or to the fixed kernel branch that matches your release. Red Hat lists Red Hat Enterprise Linux 6 with no fix planned, and Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 10, Red Hat OpenShift Container Platform 4 and Red Hat OpenShift Container Platform 5 with none available.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA Linux (Linux) Fixed in 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. 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 6 | Affected | No fix planned: Out of support scope |
| 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 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98593
- 2026-10-18 Alias added: GHSA-v4qr-c46c-6qg3
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
References
Other 7
- https://git.kernel.org/stable/c/13decd3b3b3a4d8a2e603fb8c9ffde0c6be3c225
- https://git.kernel.org/stable/c/a19bede30f0da5ae56782edac62b5998a7434cba
- https://git.kernel.org/stable/c/33f706884821da9cb55b650b7b1d4f2bdf800137
- https://git.kernel.org/stable/c/2de9c458cc49d8db6408a7c5fbf0c7c94fe4d52b
- https://git.kernel.org/stable/c/9c6af88fbefbe77608b77409df23a1617e28398c
- https://git.kernel.org/stable/c/c593f38e1cdb92f87d01be4c4e5ac12417b1454b
- https://git.kernel.org/stable/c/012bfcd5a51082d5a65f096dfb9ca652b5267965
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Sources
- CVE-2026-98593 · CVE Program
- CVE-2026-98593 · NVD
- FIRST EPSS
- GHSA-v4qr-c46c-6qg3 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98593 · Red Hat security data · CC BY 4.0
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