SB20261022162 - Reliance on undefined behavior in Linux kernel meta fbnic driver

Description

This security bulletin contains information about 1 vulnerability.

1) Reliance on undefined behavior (CVE-ID: CVE-2026-98585)

CWE-ID: CWE-758 - Reliance on Undefined, Unspecified, or Implementation-Defined Behavior

CVSSv4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to trigger undefined kernel behavior that may disrupt system operation.

The vulnerability exists due to an undefined arithmetic operation on zero in the fbnic Ethernet driver's fbnic_set_ringparam() function when processing ring-size settings supplied through ethtool. A local privileged user can submit a zero ring size that reaches roundup_pow_of_two() before minimum-size validation to trigger undefined behavior that may disrupt system operation.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0160953d8eec75c3c55562158c46442ff1fd410b
• https://git.kernel.org/stable/c/491aa3167ae02f219cb2d2de6f4196d28dca03be
• https://git.kernel.org/stable/c/92c9f2ea634d92adff5403d231ebeda683c5685a