LiveActive security incident?Get immediate response
CVE Record

CVE-2021-47088: mm/damon/dbgfs: protect targets destructions with kdamond_lock

In the Linux kernel, the following vulnerability has been resolved: mm/damon/dbgfs: protect targets destructions with kdamond_lock DAMON debugfs interface iterates current monitoring targets in 'dbgfs_target_ids_read()' while holding the corresponding 'kdamond_lock'. However, it also destructs the monitoring targets in 'dbgfs_before_terminate()' without holding the lock. This can result in a use_after_free bug. This commit avoids the race by protecting the destruction with the corresponding 'kdamond_lock'.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel memory-safety bug in DAMON’s debugfs interface. A race can let one path read monitoring targets while another frees them, creating a use-after-free condition. The supplied sources do not provide a CVSS score, confirmed impact level, or active exploitation evidence.

Executive priority

Treat this as a targeted kernel maintenance item, not an emergency based on current evidence. Prioritize affected systems that expose debugfs or rely on DAMON, and fold remediation into normal kernel patch governance unless vendor guidance raises severity.

Technical view

DAMON debugfs reads target IDs under kdamond_lock, but target destruction in dbgfs_before_terminate occurred without the same lock. The kernel fix serializes destruction with kdamond_lock to prevent a race-triggered use-after-free. The source bundle lists Linux kernel 5.15, 5.15.12, and 5.16 as affected context.

Likely exposure

Exposure is likely limited to systems running affected Linux kernels where the DAMON debugfs interface is present or used. The provided sources do not state required privileges, whether debugfs must be mounted, or distro-specific backport status.

Exploitation context

CISA KEV status is false, and the supplied sources do not cite active exploitation or public exploit use. The issue is a race condition in a kernel debugfs interface, but exploitation prerequisites are not described in the bundle.

Researcher notes

Evidence is limited to the CVE description and upstream stable commit references. No CWE, CVSS, exploit status, privilege requirement, or concrete impact chain is provided. Validation should focus on kernel provenance, backported fixes, and DAMON/debugfs exposure.

Mitigation direction

  • Check Linux kernel vendor advisories for patched builds containing the referenced fixes.
  • Prioritize kernel updates on systems using or exposing DAMON debugfs functionality.
  • Verify distribution backports rather than relying only on upstream version numbers.
  • Restrict access to debugfs according to existing hardening policy where operationally feasible.

Validation and detection

  • Inventory Linux kernel versions across servers, containers hosts, and appliances.
  • Check whether DAMON debugfs is enabled, mounted, or used on affected systems.
  • Confirm installed kernels include the referenced upstream stable commits or vendor backports.
  • Review vulnerability scanner findings against distro advisories to avoid false positives.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-47088 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux4bc05954d0076655cfaf6f0135585bdc20cd6b11, 4bc05954d0076655cfaf6f0135585bdc20cd6b11unaffected
LinuxLinux5.15, 0, 5.15.12, 5.16affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.