Unity Linux 20.1050a Security Update: kernel (UTSA-2026-146843)

high Nessus Plugin ID 373136

Synopsis

The Unity Linux host is missing one or more security updates.

Description

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-146843 advisory.

In the Linux kernel, the following vulnerability has been resolved:

net: stmmac: fix TX descriptor availability check for TSO traffic

stmmac_tso_xmit() estimates the number of free TX descriptors required by a TSO skb as:

(skb->len - proto_hdr_len) / TSO_MAX_BUFF_SIZE + 1

which assumes the payload is split into TSO_MAX_BUFF_SIZE chunks. This underestimates the descriptors actually consumed by stmmac_tso_allocator(), since each fragment is mapped individually and so it needs at least one descriptor regardless of its size. Moreover, one descriptor is used for the L2/L3/L4 headers and, when the MSS changes, one more is consumed for the MSS context descriptor.
For a highly fragmented TSO skb the check can therefore pass even when the ring has too few free slots. stmmac_tso_allocator() then writes past the available descriptors, overwriting descriptors still owned by the DMA engine, corrupting the TX ring.
Add stmmac_tso_get_num_desc() to compute the exact number of descriptors needed for the header, the linear payload and each fragment, plus the MSS context descriptor when required, and use it in the availability check.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected kernel package.

Plugin Details

Severity: High

ID: 373136

File Name: unity_linux_UTSA-2026-146843.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 10/28/2026

Updated: 10/28/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.9

Percentile: 52.44

CVSS v2

Risk Factor: Medium

Base Score: 6.6

Temporal Score: 4.9

Vector: CVSS2#AV:N/AC:H/Au:N/C:P/I:P/A:C

CVSS Score Source: CVE-2026-97953

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/UOS-Server/release, Host/UOS-Server/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 10/28/2026

Vulnerability Publication Date: 9/25/2026

Reference Information

CVE: CVE-2026-97953

Detections

Analytics