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Unity Linux 20.1070a Security Update: kernel (UTSA-2025-988929)

medium Nessus Plugin ID 273663

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-2025-988929 advisory.

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

 net: ipv4: fix memory leak in ip_mc_add1_src

 BUG: memory leak unreferenced object 0xffff888101bc4c00 (size 32):
 comm syz-executor527, pid 360, jiffies 4294807421 (age 19.329s) hex dump (first 32 bytes):
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
 01 00 00 00 00 00 00 00 ac 14 14 bb 00 00 02 00 ................
 backtrace:
 [<00000000f17c5244>] kmalloc include/linux/slab.h:558 [inline] [<00000000f17c5244>] kzalloc include/linux/slab.h:688 [inline] [<00000000f17c5244>] ip_mc_add1_src net/ipv4/igmp.c:1971 [inline] [<00000000f17c5244>] ip_mc_add_src+0x95f/0xdb0 net/ipv4/igmp.c:2095 [<000000001cb99709>] ip_mc_source+0x84c/0xea0 net/ipv4/igmp.c:2416 [<0000000052cf19ed>] do_ip_setsockopt net/ipv4/ip_sockglue.c:1294 [inline] [<0000000052cf19ed>] ip_setsockopt+0x114b/0x30c0 net/ipv4/ip_sockglue.c:1423 [<00000000477edfbc>] raw_setsockopt+0x13d/0x170 net/ipv4/raw.c:857 [<00000000e75ca9bb>] __sys_setsockopt+0x158/0x270 net/socket.c:2117 [<00000000bdb993a8>] __do_sys_setsockopt net/socket.c:2128 [inline] [<00000000bdb993a8>] __se_sys_setsockopt net/socket.c:2125 [inline] [<00000000bdb993a8>] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125 [<000000006a1ffdbd>] do_syscall_64+0x40/0x80 arch/x86/entry/common.c:47 [<00000000b11467c4>] entry_SYSCALL_64_after_hwframe+0x44/0xae

 In commit 24803f38a5c0 (igmp: do not remove igmp souce list info when set link down), the ip_mc_clear_src() in ip_mc_destroy_dev() was removed, because it was also called in igmpv3_clear_delrec().

 Rough callgraph:

 inetdev_destroy
 -> ip_mc_destroy_dev
 -> igmpv3_clear_delrec
 -> ip_mc_clear_src
 -> RCU_INIT_POINTER(dev->ip_ptr, NULL)

 However, ip_mc_clear_src() called in igmpv3_clear_delrec() doesn't release in_dev->mc_list->sources. And RCU_INIT_POINTER() assigns the NULL to dev->ip_ptr. As a result, in_dev cannot be obtained through inetdev_by_index() and then in_dev->mc_list->sources cannot be released by ip_mc_del1_src() in the sock_close. Rough call sequence goes like:

 sock_close
 -> __sock_release
 -> inet_release
 -> ip_mc_drop_socket
 -> inetdev_by_index
 -> ip_mc_leave_src
 -> ip_mc_del_src
 -> ip_mc_del1_src

 So we still need to call ip_mc_clear_src() in ip_mc_destroy_dev() to free in_dev->mc_list->sources.

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?230fa750

http://www.nessus.org/u?fd4e2ff5

https://nvd.nist.gov/vuln/detail/CVE-2021-47238

Plugin Details

Severity: Medium

ID: 273663

File Name: unity_linux_UTSA-2025-988929.nasl

Version: 1.1

Type: local

Published: 11/5/2025

Updated: 11/5/2025

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-2021-47238

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: 11/5/2025

Vulnerability Publication Date: 1/28/2022

Reference Information

CVE: CVE-2021-47238