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Unity Linux 20.1070e Security Update: kernel (UTSA-2025-987060)
medium Nessus Plugin ID 267957
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-2025-987060 advisory.In the Linux kernel, the following vulnerability has been resolved:
PCI: aardvark: Fix kernel panic during PIO transfer
Trying to start a new PIO transfer by writing value 0 in PIO_START register when previous transfer has not yet completed (which is indicated by value 1 in PIO_START) causes an External Abort on CPU, which results in kernel panic:
SError Interrupt on CPU0, code 0xbf000002 -- SError Kernel panic - not syncing: Asynchronous SError Interrupt
To prevent kernel panic, it is required to reject a new PIO transfer when previous one has not finished yet.
If previous PIO transfer is not finished yet, the kernel may issue a new PIO request only if the previous PIO transfer timed out.
In the past the root cause of this issue was incorrectly identified (as it often happens during link retraining or after link down event) and special hack was implemented in Trusted Firmware to catch all SError events in EL3, to ignore errors with code 0xbf000002 and not forwarding any other errors to kernel and instead throw panic from EL3 Trusted Firmware handler.
Links to discussion and patches about this issue:
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=3c7dcdac5c50 https://lore.kernel.org/linux-pci/[email protected]/ https://lore.kernel.org/linux-pci/[email protected]/ https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1541
But the real cause was the fact that during link retraining or after link down event the PIO transfer may take longer time, up to the 1.44s until it times out. This increased probability that a new PIO transfer would be issued by kernel while previous one has not finished yet.
After applying this change into the kernel, it is possible to revert the mentioned TF-A hack and SError events do not have to be caught in TF-A EL3.
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.
See Also
http://www.nessus.org/u?83b6721f
Plugin Details
Severity: Medium
ID: 267957
File Name: unity_linux_UTSA-2025-987060.nasl
Version: 1.1
Type: local
Published: 10/7/2025
Updated: 10/7/2025
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.4
CVSS v2
Risk Factor: Medium
Base Score: 4.6
Temporal Score: 3.4
Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C
CVSS Score Source: CVE-2021-47229
CVSS v3
Risk Factor: Medium
Base Score: 5.5
Temporal Score: 4.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
Required KB Items: Host/local_checks_enabled, Host/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 9/23/2025
Vulnerability Publication Date: 5/21/2024
Reference Information
CVE: CVE-2021-47229