Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_12: security update to 19506.505.8

high Tenable Self-Hosted Container Security Plugin ID 472181

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: bpf: Disable preemption in
__bpf_get_stack get_perf_callchain() returns a per-CPU perf_callchain_entry buffer and releases its
recursion slot via put_callchain_entry() before returning, so nothing keeps the entry reserved while
__bpf_get_stack() consumes it below. A preemptible BPF program (e.g. a non-sleepable raw tracepoint
program on a PREEMPT kernel, which runs under migrate_disable() but not preempt_disable()) can be
scheduled out between obtaining the entry and the copy. Another task scheduled on the same CPU then reuses
the same per-CPU buffer and overwrites trace->nr with a larger value. copy_len is then computed from the
inflated trace->nr and can exceed the caller's buffer, causing an out-of-bounds write in the memcpy() and
in the build_id path. The rcu_read_lock() taken here alone does not prevent this. It is only taken on the
may_fault path, and under CONFIG_PREEMPT_RCU it does not disable preemption; it merely keeps perf's
callchain buffer array alive (freed via call_rcu()) and does nothing to stop another task from reusing the
entry. Disable preemption around obtaining the callchain entry and copying it into the caller's buffer, so
the entry cannot be reused underneath us and trace->nr stays bounded by max_depth. Build ID resolution may
fault and is therefore deferred until after preemption is re-enabled; by then the instruction pointers
have already been copied into buf, so it operates only on that private copy. Note, preempt_disable() also
subsumes the buffer-lifetime guarantee the rcu_read_lock() provided, since a preempt-disabled section is
an RCU read-side critical section for the callchain buffers' call_rcu() reclaim. [ changed Fixes: commit ]
(CVE-2026-89580)

Solution

Update the sys-kernel/cchost-kernel-6_12 library and its related packages to version 19506.505.8 or later.

Plugin Details

Severity: High

ID: 472181

Version: Revision 1.2

Type: Local

Family: Google COS Security Checks

Published: 10/3/2026

Updated: 10/3/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.27

Vendor

Vendor Severity: LOW

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-2026-89580

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: 9/11/2026

Reference Information

CVE: CVE-2026-89580

Detections

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