CVE-2026-98585
Received Received - Intake

eth: fbnic driver ring size rounding vulnerability

Publication date: 2026-10-18

Last updated on: 2026-10-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: Avoid rounding zero ring sizes roundup_pow_of_two() is undefined for zero. ethtool permits a zero ring size to reach the driver, where the minimum-size check should reject it. Leave zero unchanged while rounding nonzero ring sizes. The minimum-size check then rejects zero deterministically without changing the established behavior for other values.

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Meta Information

Published
2026-10-18
Last Modified
2026-10-18
Generated
2026-10-18
AI Q&A
2026-10-18
EPSS Evaluated
N/A
NVD
CVE-2026-98585
EUVD
EUVD-2026-103630

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
Linux Linux 6cbf18a05c06090d867ef417a2a30b214d42d171
Linux Linux 6cbf18a05c06090d867ef417a2a30b214d42d171
Linux Linux 6cbf18a05c06090d867ef417a2a30b214d42d171
Linux Linux 6.15

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a flaw in the eth: fbnic driver where rounding ring sizes could lead to undefined behavior. Specifically, the function roundup_pow_of_two() does not handle zero values correctly, allowing zero ring sizes to reach the driver. Normally, a minimum-size check should reject zero, but the rounding logic could interfere with this check.

Impact Analysis

This vulnerability may cause undefined behavior in the Linux kernel's eth: fbnic driver when zero ring sizes are processed. This could lead to system instability, crashes, or unexpected behavior in network operations, potentially disrupting services relying on this driver.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the fbnic driver issue with zero ring sizes. Ensure ethtool ring size configurations are validated to prevent zero values from reaching the driver.

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