Unity Linux 20.1070a Security Update: kernel (UTSA-2026-005771)

high Nessus Plugin ID 300311

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-2026-005771 advisory.

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

netfilter: nf_tables: do not ignore genmask when looking up chain by id

When adding a rule to a chain referring to its ID, if that chain had been deleted on the same batch, the rule might end up referring to a deleted chain.

This will lead to a WARNING like following:

[ 33.098431] ------------[ cut here ]------------ [ 33.098678] WARNING: CPU: 5 PID: 69 at net/netfilter/nf_tables_api.c:2037 nf_tables_chain_destroy+0x23d/0x260 [ 33.099217] Modules linked in:
[ 33.099388] CPU: 5 PID: 69 Comm: kworker/5:1 Not tainted 6.4.0+ #409 [ 33.099726] Workqueue: events nf_tables_trans_destroy_work [ 33.100018] RIP: 0010:nf_tables_chain_destroy+0x23d/0x260 [ 33.100306] Code: 8b 7c 24 68 e8 64 9c ed fe 4c 89 e7 e8 5c 9c ed fe 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 89 c6 89 c7 c3 cc cc cc cc <0f> 0b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 89 c6 89 c7 [ 33.101271] RSP: 0018:ffffc900004ffc48 EFLAGS: 00010202 [ 33.101546] RAX: 0000000000000001 RBX: ffff888006fc0a28 RCX: 0000000000000000 [ 33.101920] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 33.102649] RBP: ffffc900004ffc78 R08: 0000000000000000 R09: 0000000000000000 [ 33.103018] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880135ef500 [ 33.103385] R13: 0000000000000000 R14: dead000000000122 R15: ffff888006fc0a10 [ 33.103762] FS: 0000000000000000(0000) GS:ffff888024c80000(0000) knlGS:0000000000000000 [ 33.104184] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 33.104493] CR2: 00007fe863b56a50 CR3: 00000000124b0001 CR4: 0000000000770ee0 [ 33.104872] PKRU: 55555554 [ 33.104999] Call Trace:
[ 33.105113] <TASK> [ 33.105214] ? show_regs+0x72/0x90 [ 33.105371] ? __warn+0xa5/0x210 [ 33.105520] ? nf_tables_chain_destroy+0x23d/0x260 [ 33.105732] ? report_bug+0x1f2/0x200 [ 33.105902] ? handle_bug+0x46/0x90 [ 33.106546] ? exc_invalid_op+0x19/0x50 [ 33.106762] ? asm_exc_invalid_op+0x1b/0x20 [ 33.106995] ? nf_tables_chain_destroy+0x23d/0x260 [ 33.107249] ? nf_tables_chain_destroy+0x30/0x260 [ 33.107506] nf_tables_trans_destroy_work+0x669/0x680 [ 33.107782] ? mark_held_locks+0x28/0xa0 [ 33.107996] ? __pfx_nf_tables_trans_destroy_work+0x10/0x10 [ 33.108294] ? _raw_spin_unlock_irq+0x28/0x70 [ 33.108538] process_one_work+0x68c/0xb70 [ 33.108755] ? lock_acquire+0x17f/0x420 [ 33.108977] ? __pfx_process_one_work+0x10/0x10 [ 33.109218] ? do_raw_spin_lock+0x128/0x1d0 [ 33.109435] ? _raw_spin_lock_irq+0x71/0x80 [ 33.109634] worker_thread+0x2bd/0x700 [ 33.109817] ? __pfx_worker_thread+0x10/0x10 [ 33.110254] kthread+0x18b/0x1d0 [ 33.110410] ? __pfx_kthread+0x10/0x10 [ 33.110581] ret_from_fork+0x29/0x50 [ 33.110757] </TASK> [ 33.110866] irq event stamp: 1651 [ 33.111017] hardirqs last enabled at (1659): [<ffffffffa206a209>] __up_console_sem+0x79/0xa0 [ 33.111379] hardirqs last disabled at (1666): [<ffffffffa206a1ee>] __up_console_sem+0x5e/0xa0 [ 33.111740] softirqs last enabled at (1616): [<ffffffffa1f5d40e>] __irq_exit_rcu+0x9e/0xe0 [ 33.112094] softirqs last disabled at (1367): [<ffffffffa1f5d40e>] __irq_exit_rcu+0x9e/0xe0 [ 33.112453] ---[ end trace 0000000000000000 ]---

This is due to the nft_chain_lookup_byid ignoring the genmask. After this change, adding the new rule will fail as it will not find the chain.

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?ec909865

http://www.nessus.org/u?467fd1ce

https://nvd.nist.gov/vuln/detail/CVE-2023-53492

Plugin Details

Severity: High

ID: 300311

File Name: unity_linux_UTSA-2026-005771.nasl

Version: 1.1

Type: local

Published: 3/3/2026

Updated: 3/3/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2023-53492

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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: 3/3/2026

Vulnerability Publication Date: 9/4/2021

Reference Information

CVE: CVE-2023-53492