Google: sys-kernel/lakitu-kernel-5_15: security update to 17523.0.0

high Tenable Self-Hosted Container Security Plugin ID 454923

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- In the Linux kernel, the following vulnerability has been resolved: net: fix use-after-free in
tw_timer_handler A real world panic issue was found as follow in Linux 5.4. BUG: unable to handle page
fault for address: ffffde49a863de28 PGD 7e6fe62067 P4D 7e6fe62067 PUD 7e6fe63067 PMD f51e064067 PTE 0 RIP:
0010:tw_timer_handler+0x20/0x40 Call Trace: <IRQ> call_timer_fn+0x2b/0x120 run_timer_softirq+0x1ef/0x450
__do_softirq+0x10d/0x2b8 irq_exit+0xc7/0xd0 smp_apic_timer_interrupt+0x68/0x120
apic_timer_interrupt+0xf/0x20 This issue was also reported since 2017 in the thread [1], unfortunately,
the issue was still can be reproduced after fixing DCCP. The ipv4_mib_exit_net is called before
tcp_sk_exit_batch when a net namespace is destroyed since tcp_sk_ops is registered befrore ipv4_mib_ops,
which means tcp_sk_ops is in the front of ipv4_mib_ops in the list of pernet_list. There will be a use-
after-free on net->mib.net_statistics in tw_timer_handler after ipv4_mib_exit_net if there are some
inflight time-wait timers. This bug is not introduced by commit f2bf415cfed7 ("mib: add net to
NET_ADD_STATS_BH") since the net_statistics is a global variable instead of dynamic allocation and
freeing. Actually, commit 61a7e26028b9 ("mib: put net statistics on struct net") introduces the bug since
it put net statistics on struct net and free it when net namespace is destroyed. Moving init_ipv4_mibs()
to the front of tcp_init() to fix this bug and replace pr_crit() with panic() since continuing is
meaningless when init_ipv4_mibs() fails. [1] https://groups.google.com/g/syzkaller/c/p1tn-
_Kc6l4/m/smuL_FMAAgAJ?pli=1 (CVE-2021-46936)

Solution

Update the sys-kernel/lakitu-kernel-5_15 library and its related packages to version 17523.0.0 or later.

Plugin Details

Severity: High

ID: 454923

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/1/2026

Updated: 10/1/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 57.12

Vendor

Vendor Severity: HIGH

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-2021-46936

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

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 7/21/2021

Reference Information

CVE: CVE-2021-46936

Detections

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