Out-of-bounds read in Linux kernel rmi_smbus block write
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: 6 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The rmi_smbus driver in the Linux kernel is affected. In rmi_smb_write_block(), the SMBus block length is computed from the original total length instead of the remaining length. On the final partial chunk, the driver reads past the end of the input buffer.
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: Input: rmi_smbus - fix out-of-bounds read in rmi_smb_write_block() When chunking writes into SMBus blocks in rmi_smb_write_block(), the loop calculates block_len using the original total length (len) instead of the remaining length (cur_len). If len is greater than 32 bytes (SMB_MAX_COUNT), block_len remains 32 for every iteration, even on the final partial chunk where fewer than 32 bytes remain. This causes smb_block_write() to read 32 bytes from the advanced data buffer pointer, reading past the end of the input buffer. Fix this by calculating block_len using cur_len and advancing the buffer and address pointers by block_len.
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 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8 or 7.3, or a later release of the same branch. The sources list no fixed version for Red Hat Enterprise Linux 7, 8, 9 and 10 and for Red Hat OpenShift Container Platform 4 and 5.
Written with Claude Haiku 5.5 from the sources below · 2026-10-30
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8, 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
- 2026-10-06 Threatist record created from CVE-2026-98204
- 2026-10-06 Alias added: GHSA-qm76-89x6-cmqm
- 2026-10-09 Affected versions changed · Red Hat
- 2026-10-09 CVSS score added · Red Hat
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-30 Affected versions changed · Red Hat
- 2026-11-01 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/d01337c0892d1509500c727edf81380777c2dd0f
- https://git.kernel.org/stable/c/7c800af1c6030a5f27d46ce7d6d5d75f9c1efaf8
- https://git.kernel.org/stable/c/29fbcf5834f0a7f74bfd017c07da2411b35a4e2a
- https://git.kernel.org/stable/c/50dd585bee7669eb165e5defcc35d17f3822cfbb
- https://git.kernel.org/stable/c/e022538e13dd1c82af5ec25ac28f12ca0ab26160
- https://git.kernel.org/stable/c/dc05ec97b8299e48e31367a9bc412c7e9c0e2b42
- https://git.kernel.org/stable/c/9f0ce5e162eed8b68345abe839c59768bc60f99a
- https://git.kernel.org/stable/c/51cfe54f815ae175c7d1126b983d4d7c89715004
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Sources
- CVE-2026-98204 · CVE Program
- CVE-2026-98204 · NVD
- FIRST EPSS
- GHSA-qm76-89x6-cmqm · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98204 · 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