dbcve.org
AndroidOperating system · Google

CVE-2022-20153

MEDIUM · 6.7 CVSS v3.1 Published 2022-06-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In rcu_cblist_dequeue of rcu_segcblist.c, there is a possible use-after-free due to improper locking. This could lead to local escalation of privilege in the kernel with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-222091980References: Upstream kernel

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Use-after-free vulnerability in the RCU (Read-Copy-Update) callback list dequeue function rcu_cblist_dequeue in rcu_segcblist.c. Improper locking allows a race condition where memory can be freed while still being accessed, potentially enabling local privilege escalation from System privileges within the Android kernel.

MitigationApply the upstream kernel patch for this vulnerability which adds proper locking synchronization around the callback list operations to prevent the race condition causing the use-after-free.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
AndroidOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check the Android kernel version
    Run 'uname -r' or read /proc/version to obtain the running kernel version
    Affected if The kernel version is any version that has not received the CVE-2022-20153 patch (no specific version numbers were provided, so any unpatched kernel is potentially affected)
  2. Identify if RCU callback handling is in use
    Examine kernel configuration for CONFIG_RCU (typically found in /proc/config.gz or boot config) - verify CONFIG_RCU is enabled
    Affected if CONFIG_RCU is not enabled, the specific vulnerable code path is not reachable, but since Android kernels typically require RCU, this is unlikely to be a mitigating factor
  3. Verify the rcu_cblist_dequeue function patch status
    Check if the fix for the race condition in kernel/rcu/rcu_segcblist.c is present by reviewing the source code or kernel symbols; look for added locking around the dequeue operation
    Affected if The kernel source or binary lacks proper locking synchronization around rcu_cblist_dequeue callback list operations (the specific fix is not present)
  4. Confirm running process context
    Verify the device is running with System-level processes accessible (this is inherent to standard Android operation)
    Affected if The device runs standard Android with System privileges available to applications, which is the baseline for this privilege escalation vector

The environment is affected if the Android kernel in use has not applied the upstream patch that adds proper locking around rcu_cblist_dequeue in the RCU callback list handling code in rcu_segcblist.c, enabling the race condition use-after-free to be exploited.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the upstream kernel patch for this vulnerability which adds proper locking synchronization around the callback list operations to prevent the race condition causing the use-after-free.

Recommended fix Moderate confidence

Android 13 or later with corresponding kernel 5.10+ that includes the RCU fix; or the latest available Android security patch level that addresses A-222091980

  1. Upgrade the Android device to the latest available Android version that includes the security patch for CVE-2022-20153
  2. Ensure the device receives the latest monthly security update from the device manufacturer
  3. For custom ROMs or development devices, apply the upstream Linux kernel patch that fixes the improper locking in rcu_cblist_dequeue (rcu_segcblist.c) to address the use-after-free vulnerability
Caveat Kernel upgrades may introduce compatibility issues with custom kernel modules or vendor-specific drivers; ensure manufacturer compatibility before updating

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Android Scoped from the published advisory
  • Consultation6.0 h
  • Implementation3.0 h
  • Testing8.0 h
  • Review / QA4.0 h
21.0 hours of engineering $3,660
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-20153 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data