CVE intelligence and bounded remediation

CVE-2021-39656 — In __configfs_open_file of file.c, there is a possible use-after-free due to improper locking

Medium CVSS 6.7

In __configfs_open_file of file.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-174049066References: Upstream kernel

Severity
Medium
CVSS
6.7 (3.1)
Published
2021-12-15
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-416, CWE-667

Affected products

  • google / android

Matched remediation archetype

Use-after-free, double free, and expired resource use

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Check exposure

  • Trace ownership, references, callbacks, asynchronous tasks, and teardown paths around the affected object or resource.
  • Identify reachable inputs and timing or state transitions that can release the object while references remain.
  • Confirm affected builds, allocators, feature flags, architectures, and process privileges.

Remediate safely

  • Apply the maintained ownership or lifetime fix and rebuild all artifacts containing the affected native code.
  • Use explicit ownership, safe reference management, cancellation and join semantics, and idempotent teardown.
  • Add deterministic lifetime tests plus isolated sanitizer and concurrency coverage for shutdown and error paths.

Authoritative sources

Complete CVE record and remediation plan

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