Out-of-bounds write in Linux kernel zone report handling
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: 1 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 6.19 is affected. The block layer zone revalidation code writes past the zones_cond array when a device reports more zones than the array can hold, because the index from the device-driven zone report is never checked against the array size. A device advertising more than UINT_MAX zones has its zone count truncated, which undersizes the array while the report walk keeps counting upward.
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: scsi: block: Fix zones_cond out-of-bounds write on zone report blk_revalidate_disk_zones() sizes the zones_cond array from the disk capacity and zone size, but the index used by blk_revalidate_zone_cond() comes from the device-driven report_zones() walk and is never checked against the array size. A device reporting more zones than fit the array makes blk_zone_set_cond() write out of bounds. One way to reach this is a zone count exceeding 32 bits: both blk_revalidate_zone_args.nr_zones and struct zoned_disk_info.nr_zones are unsigned int, so a disk advertising more than UINT_MAX zones (e.g. 2^32 + 1024 zones of one 512-byte logical block) gets its zone count truncated to a small value, undersizing the array while the report walk keeps counting upward. Check the index against the array size before storing the zone condition, and refuse to revalidate when the zone count does not fit 32 bits.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
The Linux kernel is fixed in 7.2.9 and 7.3. Red Hat lists no fix available for Red Hat Enterprise Linux 10.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 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 |
Not affected: 6 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98635
- 2026-10-18 Alias added: GHSA-xmm2-hmmq-mgf4
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Affected versions changed · Red Hat
- 2026-10-21 CVSS score added · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
References
More Linux vulnerabilities
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- 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-2026-98635 · CVE Program
- CVE-2026-98635 · NVD
- FIRST EPSS
- GHSA-xmm2-hmmq-mgf4 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98635 · 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