CVE-2022-20148

Kernel privilege escalation via F2FS discard-thread race

Published Jun 15, 2022 · Updated Aug 3, 2024

Use-after-free in the Android kernel allows local users with System execution privileges to gain elevated kernel privileges. During failed F2FS initialization, issue_discard_thread can access sbi->nm_info after f2fs_destroy_node_manager frees it because the discard thread stops too late. Exploitation requires local System execution privileges and a controllable F2FS initialization failure and race; no user interaction is required.

CVSS severity6.4
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Android kernel allows local users with System execution privileges to gain elevated kernel privileges. During failed F2FS initialization, issue_discard_thread can access sbi->nm_info after f2fs_destroy_node_manager frees it because the discard thread stops too late. Exploitation requires local System execution privileges and a controllable F2FS initialization failure and race; no user interaction is required.

The record

CVE
CVE-2022-20148
Published
Jun 15, 2022
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-362, CWE-416, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 15, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=Android kernel

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Google Cloud · Androidversion=Android kernel

Published CVSS scores

6.4Ubuntu SecurityCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-416Use After Free
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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