KVM: s390: Zero initialize data structures for inject_pfault_token
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
- —
- Fix status
- Partial Red Hat: 6 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: KVM: s390: Zero initialize data structures for inject_pfault_token __kvm_inject_pfault_token() only sets .type and .u.ext.ext_params2 of the on-stack struct kvm_s390_irq but the full ext substructure is copied into the cpu local variable on inject. ext_params and pad contain stale stack values. Interrupt delivery only uses ext_params2, so nothing leaks to the guest, but a host user can use the migration ioctls to get to the data. Fix by zero-initializing the irq struct. Do the same for the inti data structure.
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 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.112, 6.18.52, 7.2.5, 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 |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Not affected: 1 product
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-89921
- 2026-10-03 Alias added: GHSA-fm87-69w9-6w3j
- 2026-10-03 Fix available: Linux/[email protected], Linux/Linux@b8abc760fa18a389319d977834a30550b3ec18e8 · CNA
- 2026-10-03 1 new reference · CNA
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/[email protected], Linux/Linux@ab1a8a3c9971200938093370da4c67d4427c25f2 · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-30 Fix available: Linux/Linux@3da26db3323cbccf509005fdbc4ebae842d323cd, Linux/[email protected], Linux/[email protected] +3 · CNA
- 2026-10-30 3 new references · CNA
- 2026-11-04 Affected versions changed · Red Hat
- 2026-11-04 CVSS score added · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/3da26db3323cbccf509005fdbc4ebae842d323cd
- https://git.kernel.org/stable/c/5b0ae4443383fbacd905522f0c95ad6c85a3b43e
- https://git.kernel.org/stable/c/7090818ba774d254eba80979c2d4da23d91de02f
- https://git.kernel.org/stable/c/ab1a8a3c9971200938093370da4c67d4427c25f2
- https://git.kernel.org/stable/c/b8abc760fa18a389319d977834a30550b3ec18e8
- https://git.kernel.org/stable/c/9b046de62b8098af6e2ba820b125ec9dc5f162c8
- https://git.kernel.org/stable/c/134f235e0e8de54611a72d3cc3f63e5f31246baa
- https://git.kernel.org/stable/c/4e2c7f7cbc27418f9a290399b986c1b85ff93b90
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-89921 · CVE Program
- CVE-2026-89921 · NVD
- FIRST EPSS
- GHSA-fm87-69w9-6w3j · GitHub Advisory Database · CC BY 4.0
- CVE-2026-89921 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences