CVE-2026-23054

Unknown Unknown - Not Provided

Improper RSS Hash Key Validation in Linux netvsc Causes Hang

Publication date: 2026-02-04

Last updated on: 2026-02-06

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: net: hv_netvsc: reject RSS hash key programming without RX indirection table RSS configuration requires a valid RX indirection table. When the device reports a single receive queue, rndis_filter_device_add() does not allocate an indirection table, accepting RSS hash key updates in this state leads to a hang. Fix this by gating netvsc_set_rxfh() on ndc->rx_table_sz and return -EOPNOTSUPP when the table is absent. This aligns set_rxfh with the device capabilities and prevents incorrect behavior.

CVSS Scores

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Meta Information

Published

2026-02-04

Last Modified

2026-02-06

Generated

2026-07-06

AI Q&A

2026-02-04

EPSS Evaluated

2026-07-05

NVD

CVE-2026-23054

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Linux kernel's hv_netvsc network driver. It occurs because the driver accepts RSS (Receive Side Scaling) hash key updates even when the device does not have a valid RX indirection table allocated. Specifically, when the device reports only a single receive queue, the function rndis_filter_device_add() does not allocate this table. Accepting RSS hash key updates in this state causes the system to hang.

The fix involves modifying the netvsc_set_rxfh() function to check for the presence of the RX indirection table size (ndc->rx_table_sz) and return an error (-EOPNOTSUPP) if the table is absent. This ensures that RSS hash key programming is only allowed when the device supports it, preventing the hang.

Impact Analysis

This vulnerability can cause the affected Linux system to hang when RSS hash key updates are applied without a valid RX indirection table. A system hang can lead to denial of service, disrupting network operations and potentially requiring a system reboot to recover.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

The vulnerability is fixed by ensuring that RSS hash key programming is only accepted when a valid RX indirection table is present. To mitigate this vulnerability immediately, update your Linux kernel to a version that includes the fix which gates netvsc_set_rxfh() on the presence of the RX indirection table and returns -EOPNOTSUPP when the table is absent.

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