Uninitialized kernel data leak in s390 PCI SCLP error report
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
The Linux kernel s390/pci SCLP report code in report_error_write() checks only the header size, not that the buffer holds the length the report claims. A short user-space buffer makes the kernel read up to about 4K of adjacent kernel data into the SCLP report. The processing entity is privileged and can already read that page, so no data beyond its access leaks, but the read is still out of bounds. Affected are Linux kernel versions from 4.7 before the fixed versions.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: s390/pci: Fix leak of uninitialized kernel data in SCLP report While report_error_write() checks that the provided buffer is at least as large as the header struct, but not that it is large enough to contain the report with the length claimed by report->length. If user-space provides a short buffer, meaning a larger report->length than the actually written payload, up to around 4K of kernel data from past the kmalloc(len + 1) sized buffer allocated in kernfs_fop_write_iter() will leak into the SCLP report. However, as the entity processing the SCLP is privileged and able to access at least the page including the report, this does not leak data that entity could not access but it is still an out of bounds read and a malformed error report that should be rejected.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Fixed Linux kernel versions are 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.59, 7.2.13 and 7.3. The sources list no fixed version for Red Hat Enterprise Linux 7, 8, 9 and 10 or Red Hat OpenShift Container Platform 4 and 5, and Red Hat lists no available plan for them.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.59, 7.2.13, 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 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | 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: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-28 Threatist record created from CVE-2026-99124
- 2026-10-28 Alias added: GHSA-7c6q-xh8w-h79r
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-29 CVSS score added · Red Hat
- 2026-10-30 Fix available: Linux/Linux@332f2d867f64dd530517e9a58394e3eab454df12, Linux/[email protected], Linux/[email protected] +7 · CNA
- 2026-10-30 5 new references · CNA
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/ad1be38823d4b6dbc88648da296ca0c0f8824a55
- https://git.kernel.org/stable/c/61ce6f9a527932f4482ebe00847490f17d63a0d1
- https://git.kernel.org/stable/c/332f2d867f64dd530517e9a58394e3eab454df12
- https://git.kernel.org/stable/c/ff31c34e921d11c7da3d7664ce495106267ca408
- https://git.kernel.org/stable/c/eb10f25e32576bb3dbbea4457648614537f04211
- https://git.kernel.org/stable/c/ba5001db9bb23ff7d2ea328c405c287ffb07786f
- https://git.kernel.org/stable/c/126a7c227d8543e13903dd5622640c1f0fcc5a16
- https://git.kernel.org/stable/c/8ac60ae2a307a50b599bf5d300b448d638f3ba29
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-2026-99124 · CVE Program
- CVE-2026-99124 · NVD
- FIRST EPSS
- GHSA-7c6q-xh8w-h79r · GitHub Advisory Database · CC BY 4.0
- CVE-2026-99124 · 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