Google: sys-kernel/cchost-kernel-6_18, sys-kernel/csql-kernel-6_18, sys-kernel/lakitu-kernel-6_18, sys-kernel/lakitu-nc-kernel-6_18: security update to 19862.0.0

high Tenable Self-Hosted Container Security Plugin ID 470945

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: bridge: Fix sleep in atomic context in
sysfs path Since the start of the git history, brport_store() always acquired the bridge lock. Back then
this decision made sense: The bridge lock protects the STP state of the bridge and its ports and at that
time the function was only used by two STP related attributes (cost and priority). Nowadays,
brport_store() processes a lot more attributes and most of them do not need the bridge lock: * Bridge
flags: Only require RTNL. Read locklessly by the data path. Annotations can be added in net-next. * FDB
port flushing: Only requires the FDB lock. * Multicast attributes: Only require the multicast lock. *
Group forward mask: Only requires RTNL. Read locklessly by the data path. Annotations can be added in net-
next. * Backup port: Only requires RTNL. Read locklessly by the data path. This is a problem as the bridge
calls dev_set_promiscuity() when certain bridge port flags change and this function can sleep since the
commit cited below, resulting in a splat such as [1]. Fix this by reducing the scope of the bridge lock
and only take it when processing the two STP related attributes that require it. Remove the now stale
comment from br_switchdev_set_port_flag(). The SWITCHDEV_F_DEFER flag can be removed in net-next. [1] BUG:
sleeping function called from invalid context at net/core/dev_addr_lists.c:1262 in_atomic(): 1,
irqs_disabled(): 0, non_block: 0, pid: 372, name: bash preempt_count: 201, expected: 0 RCU nest depth: 0,
expected: 0 5 locks held by bash/372: #0: ffff88810c51c3f0 (sb_writers#7){.+.+}-{0:0}, at: ksys_write
(fs/read_write.c:740) #1: ffff888115ce9480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter
(fs/kernfs/file.c:343) #2: ffff88810b9fd330 (kn->active#37){.+.+}-{0:0}, at: kernfs_fop_write_iter
(fs/kernfs/file.c:80 fs/kernfs/file.c:344) #3: ffffffffa59473a0 (rtnl_mutex){+.+.}-{4:4}, at: brport_store
(net/bridge/br_sysfs_if.c:326) #4: ffff8881099d2d58 (&br->lock){+...}-{3:3}, at: brport_store
(./include/linux/spinlock.h:348 net/bridge/br_sysfs_if.c:345) Preemption disabled at: 0x0 Hardware name:
Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:94
lib/dump_stack.c:120) __might_resched.cold (kernel/sched/core.c:9163) netif_rx_mode_run
(net/core/dev_addr_lists.c:1262) netif_rx_mode_sync (net/core/dev_addr_lists.c:1428) dev_set_promiscuity
(net/core/dev_api.c:289) br_manage_promisc (net/bridge/br_if.c:135 net/bridge/br_if.c:172)
br_port_flags_change (net/bridge/br_if.c:242 net/bridge/br_if.c:747) store_learning
(net/bridge/br_sysfs_if.c:79 net/bridge/br_sysfs_if.c:235) brport_store (net/bridge/br_sysfs_if.c:346)
kernfs_fop_write_iter (fs/kernfs/file.c:352) new_sync_write (fs/read_write.c:595) vfs_write
(fs/read_write.c:688) ksys_write (fs/read_write.c:740) do_syscall_64 (arch/x86/entry/syscall_64.c:63
arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
(CVE-2026-63988)

Solution

Update the sys-kernel/cchost-kernel-6_18 library and its related packages to version 19862.0.0 or later.

Plugin Details

Severity: High

ID: 470945

Version: Revision 1.6

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/6/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.17

Vendor

Vendor Severity: LOW

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-63988

CVSS v3

Risk Factor: High

Base Score: 8.4

Temporal Score: 7.3

Vector: CVSS:3.0/AV:L/AC:L/PR:N/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: 6/22/2026

Reference Information

CVE: CVE-2026-63988

Detections

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