Detections
Analytics
Unity Linux 20.1070a Security Update: kernel (UTSA-2026-012999)
medium Nessus Plugin ID 307864
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-2026-012999 advisory.In the Linux kernel, the following vulnerability has been resolved:
btrfs: avoid potential out-of-bounds in btrfs_encode_fh()
The function btrfs_encode_fh() does not properly account for the three cases it handles.
Before writing to the file handle (fh), the function only returns to the user BTRFS_FID_SIZE_NON_CONNECTABLE (5 dwords, 20 bytes) or BTRFS_FID_SIZE_CONNECTABLE (8 dwords, 32 bytes).
However, when a parent exists and the root ID of the parent and the inode are different, the function writes BTRFS_FID_SIZE_CONNECTABLE_ROOT (10 dwords, 40 bytes).
If *max_len is not large enough, this write goes out of bounds because BTRFS_FID_SIZE_CONNECTABLE_ROOT is greater than BTRFS_FID_SIZE_CONNECTABLE originally returned.
This results in an 8-byte out-of-bounds write at fid->parent_root_objectid = parent_root_id.
A previous attempt to fix this issue was made but was lost.
https://lore.kernel.org/all/[email protected]/
Although this issue does not seem to be easily triggerable, it is a potential memory corruption bug that should be fixed. This patch resolves the issue by ensuring the function returns the appropriate size for all three cases and validates that *max_len is large enough before writing any data.
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.See Also
http://www.nessus.org/u?225c15d2
Plugin Details
Severity: Medium
ID: 307864
File Name: unity_linux_UTSA-2026-012999.nasl
Version: 1.1
Type: Local
Published: 4/21/2026
Updated: 4/21/2026
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 6.7
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-2025-40205
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/UOS-Server/release, Host/UOS-Server/rpm-list, Host/cpu
Exploit Ease: No known exploits are available
Patch Publication Date: 4/21/2026
Vulnerability Publication Date: 10/23/2025
Reference Information
CVE: CVE-2025-40205